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?1 CXA1878Q 64 pin qfp (plastic) e95933a5z-pk dolby * b-c type noise reduction system with recording/playback equalizer amplifier description the CXA1878Q is a bipolar ic with a built-in dolby b-c type noise reduction system (nr), dolby s type select switch, recording/playback equalizer, electronic volume, and bias control circuit. use of this ic in combination with two cxa1417s/q completes a dolby b-c-s type nr stereo system. features dolby b-c type nr built-in filter required for recording/playback equalizer amplifiers recording mute function (requiring only an external time constant circuit to implement soft mute) fade in/out dc controllable norm/cro 2 /metal tape mode switching function norm/high tape speed switching function dc controllable for recording level calibration (approximately 6db variable) dc controllable for high frequency equalizer amplifier gain (approximately 4db variable) playback deck a/b select switch recording volume control bias control circuit meter circuit applications recording/playback equalizer amplifier for stereo analog cassette decks (applicable to alps electric co., ltd. hadkh55 series heads) structure bipolar silicon monolithic ic absolute maximum ratings supply voltage v cc 17 v operating temperature topr ?0 to +75 ? storage temperature tstg ?5 to +150 ? allowable power dissipation p d 1020 mw operating conditions supply voltage (v cc ? v ee ) 6.5 to 8.0 v sony reserves the right to change products and specifications without prior notice. this information does not convey any license by any implication or otherwise under any patents or other right. application circuits shown, if any, are typical examples illustrating the operation of the devices. sony cannot assume responsibility for any problems arising out of the use of these circuits. * these ics are available only to the licensees of dolby laboratories licensing corporation from whom licensing and applications information may be obtained. * ?olby?and the double d symbols are trade marks of dolby laboratories licensing corporation.
?2 CXA1878Q volume pass mute nr line pb eq deck b a off on on cal mute off on cal rec pb rec pb rec-eq ams dolby b-c nr gnd cal b/c s volume cont meter2 d gnd gnd gnd volume pb eq rec-eq s b/c cal meter1 on cal off line pass mute nr pb rec rec pb moa moa on off gnd dolby b-c nr cal meter meter on mute CXA1878Q v ee metal norm cro 2 20 21 22 23 24 25 26 27 28 29 30 31 32 40 39 38 37 36 35 34 33 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 63 64 61 62 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 1 gp cal v ee dgnd rec bal rec vol meter2 meter1 deck a/b (a/b) b eq (norm/cro 2 /metal) a eq (120/70) dv cc v cc mode sw (rec/pb) vol out2 vol in2 nr pbin2 pb out2 pb inb2 pb ina2 gnd pb ina1 pb inb1 pb out1 nr pbin1 vol in1 vol out1 nr recin1 line out1 nr tch1 nr tcl1 nr out1 s in1 rec in1 nr recout1 rec out1 iref nr iref mt c1 bias m bias c bias n ams sw (off/ams/bs) pass sw (nr/mute/pass) meter sw (on/mute) speed (ns/hs) nr recin2 line out2 nr tch2 nr tcl2 nr out2 s in2 rec in2 nr recout2 rec out2 rec mute cal in mt c2 bs fb ams fb ams tc ams out s sw (s/bc/cal) nr sw (off/b/c) rec cal deck b a gnd block diagram and pin configuration
?3 CXA1878Q pin description 1 51 2 50 3 49 4 48 nr recin1 nr recin2 line out1 line out2 nr tch1 nr tch2 nr tcl1 nr tcl2 0.0v 0.0v v ee +0.4v v ee +0.4v ?6dbv ?dbv i o 40k recording equalizer amplifier input line output time constant for the hls time constant for the lls 51 1 40k 1.5k gnd 2 50 300 300 3.4k 3 49 330k 36k 13k 4 48 13.5k 480k pin no. symbol i/o z (in) equivalent circuit description typical pin voltage dc ac (ta = 25?, v cc = 7.0v, v ee = ?.0v, dv cc = 5.0v)
?4 CXA1878Q 5 47 6 46 7 45 8 44 nr out1 nr out2 s in1 s in2 rec in1 rec in2 nr recout1 nr recout2 0.0v 0.0v 0.0v 0.0v ?dbm (?dbv) ?dbm (?dbv) ?4dbv ?dbm (?dbv) o i i o 40k 50k dolby s type nr output dolby s type nr input recording equalizer amplifier input dolby nr recording signal output 5 47 gnd 1.5k 12k 192 192 20k 40k gnd 6 46 50k gnd 7 45 9.5k 8 44 gnd 1.5k 22.5k 211 211 dc ac pin no. symbol i/o z (in) equivalent circuit description typical pin voltage
?5 CXA1878Q 9 43 10 11 12 40 rec out1 rec out2 iref nr iref mt c1 mt c2 0.0v v ee +1.2v v ee +1.2v 0.0v ?dbv o o recording equalizer amplifier output reference current setting for built-in recording/playback equalizer amplifier * the reference current can be set by connecting a resistor between this pin and v ee . reference current setting for built-in dolby nr * the reference current can be set by connecting a resistor between this pin and v ee . dc cut capacitance 9 43 50k 200 200 10 192 6k 40k 11 8k 14k 300 300 12 40 dc ac pin no. symbol i/o z (in) equivalent circuit description typical pin voltage
?6 CXA1878Q 13 14 15 16 17 18 bias m bias c bias n ams sw pass sw meter sw 2.5v when open 2.5v when open o i i i recording bias control voltage output ams mode control * mode select switch for ams/bs amplifier high: bs mode medium: ams mode low: ams/bs off mode [bs mode = music signal interval detection during playback] [ams mode = music signal detection during ff/rew] pass mode control h : pass m : mute l : nr on meter mode control * meter amplifier output on/off select switch high: meter output off (mute) low : meter output on 100k 14 15 13 50k 5k 16 dgnd 5k 24k 50k 5k dgnd 5k 17 dgnd 10k 18 dc ac pin no. symbol i/o z (in) equivalent circuit description typical pin voltage
?7 CXA1878Q 19 20 23 24 speed mode sw a eq b eq 2.5v when open 2.5v when open i i i i tape speed selection * normal speed/ double speed selection high: double speed low : normal speed recording/playback mode control * recording/playback mode selection high : recording mode low : playback mode 21 22 v cc dv cc 7.0v 5.0v i i positive power supply reference power supply for mode control deck a playback equalizer amplifier control * 120s/70s selection high: 70s low : 120s (built-in equalizer amplifier flat) control of deck b playback equalizer amplifier mode, recording equalizer amplifier mode, and recording bias mode * norm/cro 2 /metal selection high : metal medium : cro 2 low : norm 10k dgnd 19 10k 2k 20 6k 10k dgnd 23 10k dgnd 24 dc ac pin no. symbol i/o z (in) equivalent circuit description typical pin voltage
?8 CXA1878Q 25 26 27 28 29 deck a/b meter1 meter2 rec vol rec bal 1.6v 2.5v when open ?.1dbv i o i i 100k 100k playback deck a/b select control * playback equalizer amplifier input selection high: pb inb low : pb ina level meter amplifier output recording volume level control high: output signal level increased low : output signal level reduced recording volume balance control high : only vol out2 output level reduced low : only vol out1 output level reduced * neither vol out1 nor 2 output levels are attenuated at the control voltage of 2.5v. 30 dgnd 0.0v connect to gnd. 10k dgnd 25 27 60k 10k 26 60k 40k 28 gnd 70k 8k 29 8k 21k 30k dv cc /2 dc ac pin no. symbol i/o z (in) equivalent circuit description typical pin voltage
?9 CXA1878Q 32 33 34 35 gp cal rec cal nr sw s sw 2.5v when open 2.5v when open 2.5v when open 2.5v when open i i i i 54k 54k 50k 50k recording equalizer amplifier high frequency calibration * controlled with dc voltages of 0 to 5v. high: high frequency level gain increased low : high frequency level gain reduced * leave this pin open when not using the high frequency calibration function. recording equalizer amplifier calibration * controlled with dc voltages of 0 to 5v. high: recording level gain increased low : recording level gain reduced * leave this pin open when not using the recording calibration function. nr control high: c type medium: b type low: nr off dolby s type selection * select the calibration mode with this pin. high: calibration medium: b-c type low: s type 31 v ee ?.0v negative power supply 54k 32 54k 33 2k 6k 34 50k dv cc /2 2k 6k 50k dv cc /2 35 dc ac pin no. symbol i/o z (in) equivalent circuit description typical pin voltage
?10 CXA1878Q 36 37 38 39 ams out ams tc ams fb bs fb 0.0v 0.0v 0.0v 0.0v o ams amplifier output time constant for the ams feedback during ams mode feedback during bs mode 10k 36 10k 10k dgnd 1k 37 40k 100k 38 2p 100k 2p 39 dc ac pin no. symbol i/o z (in) equivalent circuit description typical pin voltage
?11 CXA1878Q 41 42 64 52 63 53 cal in rec mute vol out1 vol out2 vol in1 vol in2 0.0v 0.0v 0.0v ?6dbv ?0dbv ?0dbv i i o i 10k 50k calibration signal input recording mute on/off selection * the recording mute is controlled with dc voltages of 0 to 5v. high: recording mute off low : recording mute on * soft mute and fader functions can be set by changing the time constant of the external time constant circuit. recording volume amplifier output recording volume amplifier input 10k 41 1.5k gnd 30k gnd 42 52 500 500 5p 6.5k 64 53 63 dc ac pin no. symbol i/o z (in) equivalent circuit description typical pin voltage
?12 CXA1878Q 62 54 61 55 59 60 57 56 58 nr pbin1 nr pbin2 pb out1 pb out2 pb ina1 pb inb1 pb ina2 pb inb2 gnd 0.0v 0.0v 0.0v 0.0v ?1dbv ?1dbv ?1dbv i i i 40k 50k dolby nr playback input playback equalizer amplifier output playback equalizer amplifier input ground 5k gnd 54 62 2.9k 4k gnd 35.5k 500 500 8p 30k 55 61 50k gnd 60 56 57 59 dc ac pin no. symbol i/o z (in) equivalent circuit description typical pin voltage
?13 CXA1878Q ?0dbv ?0dbv ?1dbv c8 0.1 s18 r27 10k * r18 5.1k c19 2.2 c18 0.1 c7 0.1 r26 11.6k (12k//330k) ?1dbv c17 1.0 r16 2.7k r4 100 s9 ?1dbv c16 0.1 r15 5.1k c6 0.1 r25 160k s1 ccir s5 1khz bpf din audio ??wtg s2 s3 s4 ac voltmeter distortion analyzer oscilloscope v ee r2 1.2k gnd r1 1.2k amp 2.2db audio sg dc voltmeter ?1dbv c15 0.1 c5 0.1 r24 160k r14 5.1k s15 gnd r13 5.1k ?1dbv c14 0.1 s14 r23 160k c4 0.1 ?1dbv c13 0.1 s13 r22 160k c3 0.1 r12 5.1k ?1dbv c12 1.0 s8 ?1dbv c11 0.1 s12 c2 0.1 r10 5.1k r7 100 r11 2.7k r21 11.6k (12k//330k) s7 r6 100 ?0dbv c9 1.0 r8 2.7k r30 5.1k ?6dbv c23 2.2 r28 86k (100k//620k) c21 0.1 s19 ?dbv c25 4.7 r32 2.7k s21 c27 0.1 c29 0.068 ?dbv ?dbv c31 2.2 r36 5.1k ?4dbv c35 2.2 r34 32.1k (1m//33k) c33 0.1 s23 ?dbv c37 4.7 r39 2.7k s25 ?dbv c39 2.2 r41 2.7k s27 r42 27k r45 27k c43 1.0 r29 86k ?6dbv c24 2.2 s20 r31 5.1k c22 0.1 s22 r33 2.7k ?dbv c26 4.7 c28 0.1 c30 0.068 ?dbv ?dbv c32 2.2 ?4dbv c36 2.2 s24 r37 5.1k c34 0.1 s26 ?dbv c38 4.7 r38 2.7k r35 32.1k (1m//33k) s28 ?dbv c40 4.7 r40 2.7k c41 0.1 r43 86k (100k// 620k) ?6dbv c42 2.2 r44 5.1k a gnd c50 10 r56 1k s34 s57 gnd s35 s58 s36 s51 r57 1k s37 s52 calibration dolby b/c dolby s dolby c dolby b dolby off r58 1k s54 mute on mute off v1 0.5 v2 2.5 v3 4.2 h m l c44 1.0 r47 1k c45 1.5 r49 10k c46 0.015 c47 0.1 r52 1meg r54 100k r55 1k s31 power supply +1.1dbv gnd gnd s33 s50 gnd s32 s49 gnd gnd r60 56k c52 3.3 s56 +1.1dbv gnd r59 56k c51 3.3 s55 s48 r61 1k pb in a pb in b r68 1k s47 s40 s46 r67 1k pb a eq flat pb a eq 70 metal cro 2 normal dc ammeter a dc ammeter gnd vcc v ee c49 100 gnd c48 100 gnd s45 r66 1k pb rec normal speed high speed meter on meter mute mute pass dolby nr ams mode ams off r65 1k r64 1k r63 1k r62 1k bs mode a dc ammeter 5v r53 100k s31 s38 r51 1k r48 1k r46 1k s31 s31 s31 i1 2ma r50 1k s38 20 21 22 23 24 25 26 27 28 29 30 31 32 40 39 38 37 36 35 34 33 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 63 64 61 62 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 1 gp cal v ee dgnd rec bal rec vol meter2 meter1 deck a/b b eq a eq dvcc vcc mode sw vol out2 vol in2 nr pbin2 pb out2 pb inb2 pb ina2 gnd pb ina1 pb inb1 pb out1 nr pbin1 vol in1 vol out1 nr recin1 line out1 nr tch1 nr tcl1 nr out1 s in1 rec in1 nr recout1 rec out1 iref nr iref mt c1 bias m bias c bias n ams sw pass sw meter sw speed nr recin2 line out2 nr tch2 nr tcl2 nr out2 s in2 rec in2 nr recout2 rec out2 rec mute cal in mt c2 bs fb ams fb ams tc ams out s sw nr sw rec cal * * * * * * * * c20 4.7 r19 2.7k * * r17 5.1k * * * * * * * * * * * * * * ?0dbv c10 2.2 r9 5.1k * c1 0.1 r20 10k * * * * * * s16 r3 50k s6 gnd gnd amp 0db or 30db r5 100 s10 s44 s43 s38 s41 s39 s53 s38 s17 s29 s11 * r61 50k r62 50k * * electrical characteristics measurement circuit
?14 CXA1878Q c2 75p c28 0.47 c12 4.7 r18 2k r2 12k rec gnd dolby s nr ?dbv pb only head [deck-a (r)] v ee gnd r-ch l-ch line out r20 10k headphones l2 27mh pb amp gnd r-ch l-ch line in r1 12k r8 4.7k r7 4.7k r12 100k c11 4.7 r10 100k r4 15k r3 15k ?dbv ?dbv c10 2.2 c9 2.2 r9 180k c16 2.2 r16 8.2k c18 2.2 r14 3.3k c22 0.068 c20 0.1 mpx filter ?dbv ?0dbv ?0dbv ?dbv r11 100k gnd c8 150p c14 3.3 r6 12k c7 2.2 ?1dbv pb only head gnd [deck-a (l)] pb amp c6 2.2 ?1dbv pb amp c5 2.2 ?1dbv gnd pb amp c4 2.2 ?1dbv rec/pb head [deck-b (r)] [deck-b (l)] pb rec/pb rec gnd rec/pb head [deck-b] pb rec/pb gnd erase head bias osc bias control c15 2.2 c1 75p l1 27mh ?dbv gnd c3 150p c13 3.3 r5 12k c27 2.2 r24 4.7k r23 8.2k c24 2.2 cal osc c29 2.2 r27 1k r28 10k r29 1meg r30 100k c34 0.1 c32 1.5 c33 0.015 c31 1.0 gnd r34 50k hp amp r40 220 hp amp r39 220 r38 10k r37 10k c39 10 gnd r36 50k rec cal gp cal rec calibration dv cc c38 10 c37 1 c36 1 gnd r33 50k gnd r35 50k rec level & balanse to ams control l : signal exist h : no signal meter (r) meter (l) +1dbv +1dbv c42 10 dv cc v cc c41 10 c25 0.47 r17 2k dolby s nr r19 10k r15 8.2k r13 3.3k mpx filter r22 8.2k r21 4.7k r26 20k c30 1.0 rec mute s sw nr sw deck a/b b-deck eq a-deck eq mode (rec/pb) speed meter sw pass sw ams/bs to microcomputer r32 56k c40 3.3 r31 56k c35 3.3 r25 27k c26 2.2 c23 2.2 c21 0.068 c19 0.1 c17 2.2 gp cal v ee dgnd rec bal rec vol meter2 meter1 deck a/b b eq a eq dv cc v cc mode sw vol out2 vol in2 nr pbin2 pb out2 pb inb2 pb ina2 gnd pb ina1 pb inb1 pb out1 nr pbin1 vol in1 vol out1 nr recin1 line out1 nr tch1 nr tcl1 nr out1 s in1 rec in1 nr recout1 rec out1 iref nr iref mt c1 bias m bias c bias n ams sw pass sw meter sw speed nr recin2 line out2 nr tch2 nr tcl2 nr out2 s in2 rec in2 nr recout2 rec out2 rec mute cal in mt c2 bs fb ams fb ams tc ams out s sw nr sw rec cal 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 r42 50k r41 50k application circuit
?15 CXA1878Q electrical characteristics (ta = 25?, v cc = 7.0v, v ee = ?.0v) block entire lsi entire lsi recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier current consumption (icc) operating voltage range (positive/negative dual power supplies) recording equalizer amplifier recording reference output level norm-norm mode recording equalizer amplifier recording reference input level norm-norm mode norm-norm mode rec-eq frequency response 1 (3khz, ?0db) norm-norm mode rec-eq frequency response 2 (8khz, ?0db) norm-norm mode rec-eq frequency response 3 (12khz, ?0db) cro 2 -norm mode rec-eq frequency response 1 (3khz, ?0db) cro 2 -norm mode rec-eq frequency response 2 (8khz, ?0db) cro 2 -norm mode rec-eq frequency response 3 (12khz, ?0db) metal-norm mode rec-eq frequency response 1 (3khz, ?0db) recording equalizer amplifier reference output level (315hz) (this output level is the tape reference 0db which generates magnetic flux of 250nwb/m) all of the recording equalizer amplifier blocks use this level as their reference level. input level when the reference output level is 315hz, ?.0dbv (for measurement, input a 315hz, ?4.5dbv signal to the rec eq in pins (pins 7 and 45) and then measure the output level.) norm-tape, norm-speed mode input a 3khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. norm-tape, norm-speed mode input a 8khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. norm-tape, norm-speed mode input a 12khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. cro 2 -tape, norm-speed mode input a 3khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. cro 2 -tape, norm-speed mode input a 8khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. cro 2 -tape, norm-speed mode input a 12khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. metal-tape, norm-speed mode input a 3khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. 28 6.5 ?6 ?.9 2.5 7.3 2.9 7.1 11.3 3.9 38 7.0 ?.0 ?4.5 ?.4 4.5 10.3 4.4 9.1 14.3 5.4 48 8.0 ?3 1.0 6.5 13.3 5.9 11.1 17.3 6.9 ma v dbv dbv db db db db db db db item conditions min. typ. max. unit
?16 CXA1878Q recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier metal-norm mode rec-eq frequency response 2 (8khz, ?0db) metal-norm mode rec-eq frequency response 3 (12khz, ?0db) norm-high mode rec-eq frequency response 1 (5khz, ?0db) norm-high mode rec-eq frequency response 2 (15khz, ?0db) norm-high mode rec-eq frequency response 3 (20khz, ?0db) cro 2 -high mode rec-eq frequency response 1 (5khz, ?0db) cro 2 -high mode rec-eq frequency response 2 (15khz, ?0db) cro 2 -high mode rec-eq frequency response 3 (20khz, ?0db) metal-high mode rec-eq frequency response 1 (5khz, ?0db) metal-high mode rec-eq frequency response 2 (15khz, ?0db) metal-high mode rec-eq frequency response 3 (20khz, ?0db) metal-tape, norm-speed mode input a 8khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. metal-tape, norm-speed mode input a 12khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. norm-tape, high-speed mode input a 5khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. norm-tape, high-speed mode input a 15khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. norm-tape, high-speed mode input a 20khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. cro 2 -tape, high-speed mode input a 5khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. cro 2 -tape, high-speed mode input a 15khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. cro 2 -tape, high-speed mode input a 20khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. metal-tape, high-speed mode input a 5khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. metal-tape, high-speed mode input a 15khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. metal-tape, high-speed mode input a 20khz signal (?0db level down) to the rec eq in pin and then measure the relative deviation from norm-ns, 315hz mode. 7.1 10.4 ?.3 4.0 7.4 3.9 8.6 11.4 5.9 9.5 11.8 9.1 13.4 0.2 6.5 10.9 5.4 11.1 14.9 7.4 12.0 15.3 11.1 16.4 1.7 9.0 14.4 6.9 13.6 18.4 8.9 14.5 18.8 db db db db db db db db db db db block item conditions min. typ. max. unit
?17 CXA1878Q recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording equalizer amplifier recording volume norm-norm mode rec-eq signal handling (1khz, thd = 1%, r l = 2.7k ) norm-norm mode rec-eq total harmonic distortion (1khz, 0.0db, r l = 2.7k ) norm-norm mode rec-eq s/n ratio (??wgt filter) norm-norm mode output dc offset voltage (rec out pin) norm-norm mode rec-eq mute characteristics 1 (rec-mute = 0.5v) norm-norm mode rec-eq mute characteristics 2 (rec-mute = 2.5v) norm-norm mode rec-eq rec-cal characteristics 1 (rec-cal = 5.0v) norm-norm mode rec-eq rec-cal characteristics 2 (rec-cal = 0.0v) norm-norm mode rec-eq gp-cal characteristics 1 (gp-cal = 5.0v) norm-norm mode rec-eq gp-cal characteristics 2 (gp-cal = 0.0v) recording volume amplifier recording volume characteristics 1 (rec-vol = 5.0v, rec-bal = 2.5v) norm-tape, norm-speed mode, r l = 2.7k input a 1khz signal and set the output level so that thd (total harmonic distortion) is 1%. (measure the distortion of a +11db level-up signal.) norm-tape, norm-speed mode, r l = 2.7k input a 1khz, 0db (reference input level) signal and measure the distortion. (measure the distortion as thd + n.) norm-tape, norm-speed mode, rg = 5.1k with no signal, measure the noise using the ??wgt filter. (the measured value is indicated as the relative value compared to the reference level.) norm-tape, norm-speed mode with no signal, measure the dc offset voltage of the rec out pin. norm-tape, norm-speed mode, rec-mute = 0.5v input a 1khz signal (+12db level up) and measure the attenuation when rec mute is on. (use a 1khz bpf.) norm-tape, norm-speed mode, rec-mute = 2.5v input a 1khz, 0db (reference level) signal and measure the attenuation characteristics curve of the soft mute function (when rec-mute = 2.5v). norm-tape, norm-speed mode, rec-cal = 5.0v input a 315hz signal (?0db level down) and measure the amount of change compared to when the rec-cal function is at the standard setting. norm-tape, norm-speed mode, rec-cal = 0.0v input a 315hz signal (?0db level down) and measure the amount of change compared to when the rec-cal function is at the standard setting. norm-tape, norm-speed mode, gp-cal = 5.0v input a 8khz signal (?0db level down) and measure the amount of change compared to when the gp-cal function is at the standard setting. norm-tape, norm-speed mode, gp-cal = 0.0v input a 8khz signal (?0db level down) and measure the amount of change compared to when the gp-cal function is at the standard setting. rec-vol = 5.0v, rec-bal = 2.5v input a 1khz, ?0dbv signal to the vol in pin and measure the full gain of the recording volume amplifier. 11.0 57.0 ?00 ?.1 4.8 ?.5 2.7 ?.8 8.0 12.4 0.14 65.0 10.0 ?9.9 ?.6 6.3 ?.0 4.2 ?.3 9.0 0.6 500 ?0 ?.1 7.8 ?.5 5.7 ?.8 10.0 db % db mv db db db db db db db block item conditions min. typ. max. unit
?18 CXA1878Q recording volume recording volume recording volume recording volume recording volume recording volume recording volume recording volume line amplifier line amplifier line amplifier recording volume amplifier recording volume characteristics 2 (rec-vol = 2.0v, rec-bal = 2.5v) recording volume amplifier recording volume attenuation (rec-vol = 0.0v, rec-bal = 2.5v) recording volume amplifier rec-vol signal handling (1khz, thd = 1%, r l = 2.7k ) recording volume amplifier rec-vol total harmonic distortion (1khz, ?.0dbv, r l = 2.7k ) recording volume amplifier rec-vol s/n ratio (??wgt filter) recording volume amplifier output dc offset voltage (vol out pin) recording volume amplifier rec-vol balance characteristics 1 (rec-vol = 5.0v, rec-bal = 0.0v) recording volume amplifier rec-vol balance characteristics 2 (rec-vol = 5.0v, rec-bal = 5.0v) line amplifier nr mode gain (nr pb in = 1khz, ?1.0dbv) line amplifier pass mode gain (nr pb in = 1khz, ?1.0dbv) line amplifier signal handling (1khz, thd = 1%, r l = 2.7k ) rec-vol = 2.0v, rec-bal = 2.5v input a 1khz, ?0dbv signal to the vol in pin and measure the attenuation of the recording volume amplifier. rec-vol = 0.0v, rec-bal = 2.5v input a 1khz, +2dbv signal and measure the maximum volume attenuation of the recording volume amplifier. (use a 1khz bpf.) rec-vol = 2.0v, rec-bal = 2.5v, r l = 2.7k input a 1khz signal and set the input level so that the thd is 1%. (measure the distortion when the output is +2dbv.) rec-vol = 2.0v, rec-bal = 2.5v, r l = 2.7k input a 1khz, ?0dbv signal (reference input level) and measure the distortion. (measure the distortion as thd + n.) rec-vol = 5.0v, rec-bal = 2.5v with no signal, measure the noise using an ??wgt filter. (the measured value is indicated as the relative value compared to the full-gain level.) rec-vol = 5.0v, rec-bal = 2.5v with no signal, measure the dc offset voltage of the vol out pin. rec-vol = 5.0v, rec-bal = 0.0v, (1khz bpf) input a 1khz, +2dbv signal and measure the attenuation of vol out 1. (input a ?0dbv signal and confirm that there is no attenuation at vol out 2.) rec-vol = 5.0v, rec-bal = 5.0v, (1khz bpf) input a 1khz, +2dbv signal and measure the attenuation of vol out 2 . (input a ?0dbv signal and confirm that there is no attenuation at vol out 1.) nr mode input a 1khz, ?1dbv signal to the nr pb in pin and measure the gain. pass mode input a 1khz, ?1dbv signal to the nr pb in pin and measure the gain. pass mode, r l = 2.7k input a 1khz signal and set the output level so that the thd is 1%. (measure the distortion when the output is +1dbv.) ?.4 2.0 80 ?50 6.0 6.0 12.0 ?.4 104.7 3.41 0.09 97.5 4.2 ?3.2 ?3.2 7.0 7.0 15.5 ?.4 ?0 0.5 150 ?0 ?0 8.0 8.0 db db dbv % db mv db db db db db block item conditions min. typ. max. unit
?19 CXA1878Q line amplifier line amplifier line amplifier line amplifier level meter level meter level meter level meter playback equalizer amplifier playback equalizer amplifier playback equalizer amplifier line amplifier line amplifier total harmonic distortion (1khz, ?1.0dbv, r l = 2.7k ) line amplifier line amplifier s/n ratio (??wgt filter) line amplifier output dc offset voltage (line out pin) line amplifier mute mode characteristics (1khz bpf) level meter amplifier level meter characteristics 1 (pass in = 1khz, ?1dbv) level meter amplifier level meter characteristics 2 (pass in = 1khz, ?1dbv) level meter amplifier level meter cal characteristics (pass in = 1khz, ?8dbv) level meter amplifier level meter mute characteristics (pass in = 1khz, +1.0dbv) 120s, deck-a mode playback reference output level (playback equalizer amplifier gain) playback equalizer amplifier pb-eq frequency response 1 120s-ns, deck-a mode playback equalizer amplifier pb-eq frequency response 2 70s-ns, deck-a mode pass mode, r l = 2.7k input a 1khz, ?1dbv signal (reference input level) and measure the distortion. (measure the distortion as thd + n.) pass mode, rg = 5.1k with no signal, measure the noise using the ??wgt filter. (the measured value is indicated as the relative value compared to the reference level. pass mode with no signal, measure the dc offset voltage of the line out pin. mute mode input a 1khz, +1dbv signal to the nr pb in pin and measure the attenuation when line mute is on. (use a 1khz bpf.) meter on, cal off, pb input a 1khz, ?1dbv signal to the nr pb in pin and measure the output dc voltage at the meter pin. meter on, cal off, pb input a 1khz, ?1dbv (?0db level down) signal to the nr pb in pin and measure the output dc voltage at the meter pin. meter on, cal on, rec input a 1khz, ?8dbv (?7db level down) signal to the nr pb in pin and measure the output dc voltage at the meter pin. meter mute on, pb input a 1khz, +1dbv (12db level up) signal to the nr pb in pin and measure the output dc voltage at the meter pin. deck-a, a-eq = 120s, norm-speed mode input a 315hz, ?1dbv (reference input level) signal to the pb in pin and measure the output level. deck-a, a-eq = 120s, norm-speed mode input a 5khz, ?1dbv (reference input level) signal and then measure the relative deviation from the 120s-ns, 315hz mode. deck-a, a-eq = 70s, norm-speed mode input a 5khz, ?1dbv (reference input level) signal and then measure the relative deviation from the 120s-ns, 315hz mode. 80 ?00 1.34 0.2 1.3 ?1.9 ?.0 ?.7 0.07 84.1 0 ?11 1.64 0.5 1.6 3.0 ?0.9 0.0 ?.2 1.0 200 ?0 1.94 0.8 1.9 50.0 ?.9 1.0 ?.7 % db mv db v v v mv dbv db db block item conditions min. typ. max. unit
?20 CXA1878Q playback equalizer amplifier playback equalizer amplifier playback equalizer amplifier playback equalizer amplifier playback equalizer amplifier playback equalizer amplifier playback equalizer amplifier ams/bs amplifier ams/bs amplifier ams/bs amplifier playback equalizer amplifier pb-eq frequency response 3 120s-hs, deck-a mode playback equalizer amplifier pb-eq frequency response 4 70s-hs, deck-a mode 120s-ns, deck-a mode pb-eq signal handling (1khz, thd = 1%, r l = 2.7k ) 120s-ns, deck-a mode pb-eq total harmonic distortion (1khz, 0.0db, r l = 2.7k ) 120s-ns, deck-a mode pb-eq s/n ratio (??wgt filter) 120s-ns, deck-a mode output dc offset voltage (pb out pin) recording equalizer amplifier deck-a/b switching characteristics 120s-ns, deck-b mode ams/bs amplifier ams signal detection level ams mode ams/bs amplifier bs signal detection level bs mode ams/bs amplifier ams output leak current (ams out pin) deck-a, a-eq = 120s, high-speed mode input a 5khz, ?1dbv (reference input level) signal and then measure the relative deviation from the 120s-ns, 315hz mode. deck-a, a-eq = 70s, high-speed mode input a 5khz, ?1dbv (reference input level) signal and then measure the relative deviation from the 120s-ns, 315hz mode. deck-a, a-eq = 120s, norm-speed mode, r l = 2.7k input a 1khz signal and set the output level so that the thd is 1%. (measure the distortion of a +12db level-up signal.) deck-a, a-eq = 120s, norm-speed mode, r l = 2.7k input a 1khz, ?1dbv (reference input level) signal and measure the distortion. (measure the distortion as thd + n.) deck-a, a-eq = 120s, norm-speed mode, rg = 5.1k with no signal, measure the noise using the ??wgt filter. (the measured value is indicated as the relative value compared to the reference level.) deck-a, a-eq = 120s, norm-speed mode with no signal, measure the dc offset voltage of the pb out pin. deck-b, b-eq = norm-tape, norm-speed mode input a 1khz, ?1dbv (reference input level) signal to the deck-b side and then measure the relative deviation from the deck-a, 120s-ns, 315hz mode. ams mode, fin = 5khz, reference level ?1dbv input level when the ams out pin level changes from high to low. input the signal to the nr pb in pin and measure the level at the ams out pin. bs mode, fin = 5khz, reference level ?1dbv input level when the ams out pin level changes from high to low. input the signal to the nr pb in pin and measure the level at the ams out pin. ams off mode input a 5khz, ?1dbv signal to the nr pb in pin and measure the current flowing to the ams out pin. ?.8 ?0.1 12 70 ?00 ?.0 ?5.0 ?5.5 ?.3 ?.6 22 0.03 75.6 ? 0.0 ?0.0 ?0.5 0.88 ?.8 ?.1 0.5 200 1.0 ?.0 ?5.5 1.0 db db db % db mv db db db ? block item conditions min. typ. max. unit
?21 CXA1878Q ams/bs amplifier bias sw bias sw bias sw dolby dolby dolby dolby dolby dolby dolby dolby ams/bs amplifier ams output saturation voltage (ams out pin) bias n output voltage (normal mode) bias c output voltage (cro 2 mode) bias m output voltage (metal mode) dolby level rec mode rec in level rec mode cal in level pb mode pb in level b type encoding boost characteristics 1 b type encoding boost characteristics 2 b type encoding boost characteristics 3 b type encoding boost characteristics 4 ams mode input a 5khz, ?1dbv signal to the nr pb in pin and measure the output voltage when a 1ma current flows to the ams out pin. input a 2ma signal to the bias n pin and measure the dc output voltage at the bias n pin. input a 2ma signal to the bias c pin and measure the dc output voltage at the bias c pin. input a 2ma signal to the bias m pin and measure the dc output voltage at the bias m pin. rec mode, nr off 1khz, assume dolby level of ?dbm as 0db. rec mode, nr off, f = 1khz input a signal to the rec in pin and measure the level at which the level of the dolby out pin reaches ?dbm. rec mode, nr off, f = 1khz input a signal to the cal in pin and measure the level at which the level of the dolby out pin reaches ?dbm. pb mode, nr off, f = 1khz input a signal to the nr pb in pin and measure the level at which the level of the dolby out pin reaches ?dbm. rec, dolby b type mode input a 500hz, ?5db signal from the rec in pin and measure the boost at the rec out pin. rec, dolby b type mode input a 5khz, ?5db signal from the rec in pin and measure the boost at the rec out pin. rec, dolby b type mode input a 10khz, ?0db signal from the rec in pin and measure the boost at the rec out pin. rec, dolby b type mode input a 10khz, 0db signal from the rec in pin and measure the boost at the rec out pin. ?6 ?6 ?1 1.4 3.9 9.7 ?.1 0.17 0.4 0.4 0.4 ?.0 ?5 ?5 ?0 2.9 5.4 10.4 0.4 1.0 0.6 0.6 0.6 ?4 ?4 ? 4.4 6.9 11.4 1.9 v v v v dbm dbm dbm dbm db db db db block item conditions min. typ. max. unit
?22 CXA1878Q dolby dolby dolby dolby dolby dolby dolby dolby dolby dolby dolby c type encoding boost characteristics 1 c type encoding boost characteristics 2 c type encoding boost characteristics 3 c type encoding boost characteristics 4 c type encoding boost characteristics 5 c type encoding boost characteristics 6 pb mode frequency response rec mode signal handling nr off total harmonic distortion dolby b type total harmonic distortion dolby c type total harmonic distortion rec, dolby c type mode input a 500hz, ?0db signal from the rec in pin and measure the boost at the rec out pin. rec, dolby c type mode input a 500hz, ?5db signal from the rec in pin and measure the boost at the rec out pin. rec, dolby c type mode input a 2khz, ?0db signal from the rec in pin and measure the boost at the rec out pin. rec, dolby c type mode input a 2khz, ?5db signal from the rec in pin and measure the boost at the rec out pin. rec, dolby c type mode input a 5khz, ?5db signal from the rec in pin and measure the boost at the rec out pin. rec, dolby c type mode input a 10khz, 0db signal from the rec in pin and measure the boost at the rec out pin. pb, dolby c type mode input a 20khz, ?0dbm signal from the nr pb in pin and measure the relative deviation from the rec out output nr off mode. rec, nr off mode input a 1khz signal and set the output level so that the thd is 1%. (measure the distortion using a +13.5db level-up signal from the reference.) rec, nr off mode input a 1khz, +10db signal from the rec in pin and measure the distortion. (measure the distortion as thd + n.) rec, dolby b type mode input a 1khz, +10db signal from the rec in pin and measure the distortion. (measure the distortion as thd + n.) rec, dolby c type mode input a 1khz, +10db signal from the rec in pin and measure the distortion. (measure the distortion as thd + n.) 14.2 7.2 18.7 5.4 3.5 ?.5 ?.5 13.5 16.2 9.2 20.7 7.4 5.5 ?.5 0 15.4 0.04 0.06 0.09 18.2 11.2 22.7 9.4 7.5 ?.5 1.5 0.5 0.5 0.5 db db db db db db db db % % % block item conditions min. typ. max. unit
?23 CXA1878Q dolby dolby dolby dolby control circuit control circuit control circuit control circuit control circuit rec mode dolby c type s/n ratio pb mode recording ? playback crosstalk rec mode playback ? recording crosstalk rec mode output dc offset voltage (rec out pin) mode control control circuit high level mode control control circuit medium level mode control control circuit low level mode control control circuit high level mode control control circuit low level rec, dolby c type mode, rg = 5.1k with no signal, measure the noise using the ccir/arm filter. (the measured value is indicated as the relative value compared to the dolby out level.) pb, nr off mode input a 1khz, +10db signal from the rec in pin and measure the rec ? pb crosstalk. (use a 1khz bpf.) rec, nr off mode input a 1khz, +10db signal from the nr pb in pin and measure the pb ? rec crosstalk. (use a 1khz bpf.) rec mode, nr off ? c type with no signal, measure the deviation in the output dc offset voltage at the rec out pin when switching from nr off mode to c type mode. nr sw, s sw, deck a/b, eq, b eq, and pass sw pin voltages nr sw, s sw, deck a/b, eq, b eq, and pass sw pin voltages nr sw, s sw, deck a/b, eq, b eq, and pass sw pin voltages ams sw, mode sw, speed, and meter sw pin voltages ams sw, mode sw, speed, and meter sw pin voltages 60.0 ?00 4.2 2.2 0.0 3.5 0.0 61.0 ?7.5 ?13 0.0 ?0 ?0 100 v cc 2.8 0.5 v cc 0.5 db db db mv v v v v v ternary switching binary swithing block item conditions min. typ. max. unit
?24 CXA1878Q c4 200p r11 18k a deck b deck b eq (n/c/m) a eq (120/70) deck a/b (a/b) speed (ns/hs) rec mute rec vol rec bal meter sw (on/mute) pass sw (nr/mute/pass) nr sw (off/b/c) mode sw (rec/pb) ams sw (off/ams/bs) s sw (s/bc/cal) control to control ic vol in gnd dvcc r1 50k r2 50k to line in gnd osc ?dbv 600 10k * sourse impedance 10k w ?0dbv r12 6.5k ?0dbv vgs (c) vgs (b) 1 gm1 rva r13 6.5k r15 3.3k ?4dbv gnd r20 2k r18 6.2k c6 2.2 vol out nr recin cal in ?0dbv moa gnd (vg) vcc vcc v ee v ee dv cc gnd gnd iref (rec/pb) dvcc dgnd nr iref c3 2.2 r6 27k r5 20k bias vgs (c) ?6dbv vgs (c) vgs (c) vgs (c) r19 4k r16 36k (?0dbm) ?1dbv for r-ch r17 40k r21 10k ?6dbv (?5dbm) on off rec pb c8 r23 (?dbm) rec & cal pb rec/pb vgs (c) r25 1.5k r26 12k r24 22.5k r22 1.5k vgs (c) nr out dolby s nr s in (?dbm) vgs (c) r31 40k pea gmb vgs (c) r10 2k c5 2.2 gnd (a) gnd ?1dbv ?1dbv vgs (c) r8 50k r9 50k ?1dbv c2 2.2 c1 2.2 r14 30k ?1dbv pre d1 pb ina pb inb ?1dbv pb amp 1 sum ams s sw cal s-nr b/c-nr bc/s/cal ?dbv (?dbm) ?dbv r27 40k (?0dbm) ?1dbv pb only head [deck-a] ?1dbv r23 40k r28 12.5k r29 100k ?5dbv vgs (b) for r-ch v ee r32 100k pb out nrpb in nr tch nr tcl ams fb bs fb v ee c7 0.1 c8 0.068 gnd 1 c10 106p r30 10k c9 0.015 gnd r33 1k c11 1.5 ?5dbv ?6dbv ?5dbv ams tc line out mt c meter comp mtr line dgnd q dgnd det r44 3.3k vgs (c) nr/pass/mute ?dbv r42 2.9k r39 5k r46 2k r47 12k meter vgs (c) vgs (b) cal off on meter nr pass off on ?dbv (?dbm) off on off on meter cal mute vgs (b) nr/pass /mute (?dbm) ?dbv gnd r54 14k r58 36k r59 10k dgnd r62 150 r60 10k +1.1dbv (1.6v) v ee q q q nr pass mute b eq metal cro 2 norm vcc rec gm5 vgs (c) r35 4.7k r43 2.5k c12 2.2 gnd gnd for r-ch r-ch l-ch line out from line out vm ?dbv * load impedance 47k w r45 12k hp amp r48 100k nr recout r34 8.2k gnd rec in gnd c14 2.2 r37 10k c13 0.47 gm2 1 r57 40k r41 20k r40 15k rea vgs (b) rec out r63 50k r38 50k c17 200p ?dbv ?dbv ?.5dbv ?4dbv ?dbv c20 100p gnd (a) vgs (c) ?dbv r52 20k r51 20k vgs (c) c19 100p vgs (c) +6dbv ?dbv gm4 gm3 1 1 bpf gnd (a) gnd (a) r53 8k r56 24k calibration gnd dvcc r67 50k rec cal gp cal r65 50k bias-n bias-c bias-m ams out dvcc r64 100k to ams control ?dbv to meter ic gnd r61 56k gnd c21 3.3 r36 1meg c15 0.1 dvcc ?dbv c16 4.7 gnd c18 1.0 r50 4.7k gnd r55 220 gnd for r-ch headphones r66 12k c24 75p gnd gnd c23 150p c22 3.3 l1 27mh pb rec rec/pb rec/pb head [deck-b] bias osc pb amp bias control gnd 47k mpx filter dolby b/c-nr ants ssk hls vf lls vf ?1dbv ams/bs bs ams v ee v ee v ee dvcc v ee v ee r49 10k gnd gnd for r-ch r-ch l-ch line in r4 15k r3 180k r7 50k gnd description of operation the CXA1878Q is a dolby b-c type nr system with a built-in recording/playback equalizer amplifier, electronic volume, ams, bias sw, and meter circuit. in addition, this chip also contains an s type (cxa1417s/q) select switch, enabling the construction of a 2-channel dolby b-c-s type nr system by using the CXA1878Q together with two cxa1417s/q encoder units. the CXA1878Q has the circuit configuration shown in fig. 1. fig. 1. functional block diagram
?25 CXA1878Q 1. reference levels (1) recording equalizer amplifier output level (315hz, ?dbv) [ * when the recording equalizer amplifier input level is ?4dbv] (2) playback equalizer amplifier output level (315hz, ?1dbv) [ * when the playback equalizer amplifier input level is ?1dbv] (3) dolby the dolby level is measured at the recording output pin (rec out) at ?dbm (388mvrms) in the nr off mode. reference levels for the recording input pin (line in), playback input pin (pb in) and line output pin (line out) are defined as the levels which apply the dolby level to rec out in the nr off mode. 2. system control methods (1) mode settings table * the nr sw (pin 34) operates only when the nr s sw (pin 35) is set to medium. (2) mode setting pin control voltage pin no. symbol pin voltage low medium high remarks 34 35 16 20 19 25 23 24 17 18 nr sw nr s sw ams sw mode sw speed deck a/b a eq b eq pass sw meter sw dolby nr off dolby s ams off pb normal speed pb in a pb in a eq flat pb in b eq flat rec eq normal bias sw normal dolby nr meter on dolby nr on b type dolby b-c * ams mode pb in b eq 70 rec eq cro 2 bias sw cro 2 mute dolby nr on c type calibration bs mode rec high speed pb in b pb in a eq 70 pb in b eq 70 rec eq metal bias sw metal pass meter off 3-state 3-state 3-state 2-state 2-state 2-state 2-state 3-state 3-state 2-state note: when 3-state input pins are open, the pin voltage is medium. control voltage high level medium level low level high level low level 4.2 2.2 0.0 3.5 0.0 v cc 2.8 0.5 v cc 0.5 3-state 2-state min. max.
?26 CXA1878Q 3. recording mute function the CXA1878Q recording mute function is implemented by using a built-in recording mute circuit which varies the recording equalizer amplifier gain according to the magnitude of the dc voltage applied to the rec mute pin just like an electronic volume control. also, any desired soft mute or fader can be freely set depending on momentary changes in the dc voltage applied to the rec mute pin. fig. 2 illustrates the recording mute waveforms. * 1 although the above range of voltages can be input to the control pin, the controllable input voltage range is as follows. 2.5v < vup 5.0v dgnd vdown < 2.5v * 2 control voltages for this ic are referenced to the dgnd pin (pin 30). also note that when not using this recording level calibration function, simply leave the rec cal pin (pin 33) open, so that the voltage of the rec cal pin is matched to the internal reference voltage (2.5v), with the recording level set for the standard gain. pin no. symbol 42 rec mute pin voltage (v) remarks recout attenuation (db) norm tape, norm-speed, f = 1khz decrease <<<< increase 0.0 0.5 2.5 4.5 5.0 less than ?0 ?0 4. recording level calibration the CXA1878Q allows the recording level to be finely adjusted with a dc voltage. therefore, the recording level can be varied by approximately 6db simply by applying dc voltages of 0 to 5v (for dual power supply) to the rec cal pin (pin 33). the table below shows the input range of control voltages with the power supplies used. * 1 output level rec cal pin voltage down (vdown) dgnd to 2.5v typ. 2.5v * 2 up (vup) 2.5v to v cc fig. 2. recording mute waveform rec mute control voltage
?27 CXA1878Q 5. high frequency calibration the CXA1878Q allows the high frequency response of the recording equalizer to be finely adjusted with a dc voltage. therefore, the recording level in high frequencies (peak) can be varied by approximately 4db simply by applying dc voltages of 0 to 5v (for dual power supply) to the gp cal pin (pin 32). the table below shows the input range of control voltages with the power supplies used. * 3 gain [db] rec cal rec cal rec cal rec cal rec cal rec cal gp cal gp cal gp cal frequency [hz] output level gp cal pin voltage down (vdown) dgnd to 2.5v typ. 2.5v * 4 up (vup) 2.5v to v cc * 3 although the above range of voltages can be input to the control pin, the controllable input voltage range is as follows. 2.5v < vup 5.0v dgnd vdown < 2.5v * 4 control voltages for this ic are referenced to the dgnd pin (pin 30). also note that when not using this high frequency calibration function, simply leave the gp cal pin (pin 32) open, so that the voltage of the gp cal pin is matched to the internal reference voltage (2.5v), with the high frequency equalizer amplifier characteristics set for the standard gain. fig. 3. conceptual diagram of the recording level/high frequency calibration functions 6. meter circuit the CXA1878Q has a built-in full-wave rectifier circuit for the level meter. therefore, a dc voltage can be obtained by attaching time constants to the meter 1 and 2 output pins. the output voltage is set to 1.6v (+1.1dbv) during reference input. (for an external time constant of 56k , 33f) the mt c pin detects only the ac component. the low frequency cut-off is determined with the capacitor connected to this pin and the 14k internal resistor. (approximately 10hz for 1f) 7. recording volume control circuit the CXA1878Q adjusts the size of the recording signal with a built-in control circuit. therefore, the gain can be controlled by applying the voltage between dv cc and dgnd to the rec vol pin (pin 28). (a 0db signal is output when voltage of 2.0v is applied.)
?28 CXA1878Q 8. recording volume balance circuit the CXA1878Q contains a circuit which controls the balance between channels 1 and 2 of the recording volume. therefore, the balance between channels 1 and 2 can be controlled by applying the voltage between dv cc and dgnd to the rec bal pin (pin 29). (signals which are not attenuated by the balance circuit are output from both channels when this control pin is open or when a voltage of dv cc /2 is applied.) rec vol control voltage pin no. symbol 28 rec vol pin voltage (v) remarks volout1 and 2 attenuation (db) balance = 2.5v, f = 1khz decrease <<<< increase 0.0 0.5 2.0 4.5 5.0 less than ?6 ?6 0.0 9.0 pin no. symbol 29 rec bal pin voltage (v) remarks volout2 attenuation (db) rec vol = 5v, f = 1khz volout1 attenuation (db) rec vol = 5v, f = 1khz increase >>>> decrease 0.0 0.5 2.5 4.5 5.0 0.0 0.0 0.0 ?3 less than ?3 decrease <<<< increase less than ?3 ?3 0.0 0.0 0.0 balanc control voltage 9. bias osc power supply control circuit the CXA1878Q contains a switch circuit that selects the supply voltage for the bias oscillator. the supply voltage can be controlled with the b eq pin (pin 24). the maximum output current is 2ma.
?29 CXA1878Q 10. ams circuit the CXA1878Q has the music sensor circuit. comp nr pbin1 nr pbin2 0db 0db 16khz lpf window comp op amp 100k w 1k w ams tc ams out c3 r3 dv cc g1 r1 c1 g2 r2 c2 [ * 1] [ * 1] [ * 2] [ * 2] 54 62 36 37 the broken line shows the case detection level has changed. window comp detection level (sensitivity) ams out ams on ams tc pin voltage after integration comp detection level fig. 4. ams circuit block diagram (1) ams on operation the signal input from pb nr in first passes through the lpf, then through the hpf/sensitivity setting amplifier, and then through the window comparator where it is formed into a pulse wave. (see fig. 5) this signal which has been formed into a pulse wave is integrated by a capacitor connected to the ams tc pin (pin 37) and then input to the comparator. (see fig. 6) ams out turns on when the ams tc pin voltage falls below the comparator threshold value. (when the sensitivity changes, the pulse width also changes.) fig. 5. conceptual diagram of window comparator operation fig. 6. conceptual diagram of ams out operation
?30 CXA1878Q (2) ams off operation when the input signal disappears, the capacitance connected to the ams tc pin (pin 37) is discharged, causing the tc pin voltage to rise above the threshold value and turn ams off. (3) ams gain setting method the ams gain (g1/g2 mode gain) adjustment can be determined by external resistances r1 and r2. in addition, ams gain is expressed by the following equations. g1 = 20 log r1 + 100k (internal resistance) db r1 g2 = 20 log r2 + 100k (internal resistance) db r2 db g1 nor (bs) g2 ff (ams) [ * 2] [ * 2] [ * 1] [ * 1] frequency (4) ams low frequency cut-off setting method the ams low frequency cut-off adjustment can be determined by external resistances r1 and r2 and capacitances c1 and c2. (5) relationship between response time and sensitivity the ams on time is determined by the width of the pulse obtained by applying the input signal to the window comparator. the pulse emitted from the window comparator becomes extremely small near the detection level, and some time is required for this pulse to be integrated by the external capacitance, thus lengthening the response time. * response times can be adjusted to approximately the same value by adjusting the ams sensitivity with resistances r1 and r2 to match the various ics. also, the ams off time is determined by the external time constant (r3, c3). notes on operation temperature characteristics and accuracy of the recording equalizer amplifier the temperature characteristics of the built-in monolithic filter and the filter cut-off frequency depend on the 27k external resistance connected to the iref pin (pin 10). also, the recording equalizer amplifier frequency response depends on unevenness in the absolute, as well as relative values of the internal capacitance. furthermore, the high frequency response indicates a high element sensitivity at the filter because the band-pass filter q is high. compared to low frequency, although the unevenness inherent in the ic is more likely to occur, this occurs relatively, and not individually for channels 1 and 2.
?31 CXA1878Q example of representative characteristics ?.0 ? ? ? 0 2 4 6 8 ?.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 315hz 8khz v cc , v ee = 7.0v (tape) (speed) mode: norm - norm gp cal pin = open 0db = rec cal and gp cal pin = open ?0db (at 315hz,?dbv) output level vs. rec cal pin voltage output level [db] rec cal pin voltage [v] ?0.0 100 1k 10k 100k 0.0 10.0 20.0 30.0 40.0 rec cal = 5.0v rec cal = 2.5v rec cal = 0.0v v cc , v ee = 7.0v (tape) (speed) 0db = norm - norm, 315hz, ?3dbv (output reference) rec cal and gp cal = open gp = 5.0v 2.5v 0.0v rec cal and gp cal frequency response output response [db] frequency [hz] ?0.0 100 1k 10k 100k 0.0 10.0 20.0 30.0 v cc , v ee = 7.0v 0db = norm - norm, 315hz, ?3dbv (output reference) (tape) (speed) norm - high cro 2 - high metal - high recording equalizer amplifier frequency response (high speed) frequency [hz] output response [db] a a a a a a a a aa a a a a a aa a a ?.0 ? ? ? 0 2 4 6 8 ?.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 315hz 3khz 8khz 12khz v cc , v ee = 7.0v (tape) (speed) mode: norm - norm rec cal pin = open 0db = rec cal pin and gp cal pin = open ?0db (at 315hz,?dbv) output level vs. gp cal pin voltage output level [db] gp cal pin voltage [v] ?0.0 100 1k 10k 100k 0.0 10.0 20.0 30.0 recording equalizer amplifier frequency response (normal speed) output response [db] frequency [hz] v cc , v ee = 7.0v 0db = norm - norm, 315hz, ?3dbv (output reference) (tape) (speed) norm - norm cro 2 - norm metal - norm
?32 CXA1878Q ?0 ?0 ?0 ?0 0.2 0.5 1.0 2.0 0 5.0 v cc , v ee = 7.0v (tape) (speed) mode: norm - norm, 0db = 1khz, +12db (at 315hz, 3dbv) f = 1khz output level vs. rec mute pin voltage 2 output level [db] rec mute pin voltage [v] ?00 ?0 ?0 ?0 0.0 1.0 2.0 3.0 ?0 4.0 5.0 6.0 0 v cc , v ee = 7.0v (tape) (speed) mode: norm - norm, 0db = 1khz, +12db (at 315hz, ?dbv) f = 1khz output level vs. rec mute pin voltage 3 output level [db] rec mute pin voltage [v] ?0 ?0 ?0 ?0 0.2 0.5 1.0 2.0 0 5.0 ?0 ?0 ?0 ?0 v cc , v ee = 7.0v dv cc = +5.0v input : volume in = ?0dbv, f = 1khz rec bal pin voltage = 2.5v recording volume characteristics volume output [db] rec level pin voltage [v] recording volume balance characteristics ?00 ?0 ?0 ?0 0.0 1.0 2.0 3.0 ?0 4.0 5.0 0 ?0 ?0 ?0 ?0 ?0 v cc , v ee = 7.0v dv cc = +5.0v input : volume in = ?0dbv, f = 1khz rec vol pin voltage = +5.0v 1ch 2ch recording volume output level [db] balance control pin voltage [v] 0 100 1k 10k 100k 5 10 15 v cc , v ee = 7.0v (tape) (speed) mode: norm - norm, 0db = ?dbv (rec out pin) thd + n = 1% 315hz 1khz maximum output level (db) load resistance r l [w] recording equalizer amplifier load characteristics 0 20 40 60 0.0 1.0 2.0 3.0 80 4.0 5.0 6.0 100 output level vs. rec mute pin voltage 1 output level [%] rec mute pin voltage [v] v cc , v ee = 7.0v (tape) (speed) mode: norm - norm, 0db = 1khz, +12db (at 315hz, ?dbv) f = 1khz
?33 CXA1878Q 100 1k 10k 100k 0.0 2.0 4.0 6.0 8.0 10.0 v cc , v ee = 7.0v 0db = ?1dbv (nr pb in) pass mode 10.0 1.0 0.1 0.01 ?6 ?2 ? ? 0 4 8 12 16 v cc , v ee = 7.0v mode = pass mode 0db = ?dbv (line out) 100hz 1khz 10khz 25.0 21.0 17.0 13.0 9.0 5.0 100 1k 10k 100k 35s 60s 70s 120s v cc , v ee = 7.0v (tape) (speed) 0db = norm - norm, 315hz, ?1dbv (input reference) playback equalizer amplifier frequency response output response [db] frequency [hz] t.h.d + n [%] 10 1.0 0.1 0.01 ?0 ?0 ?0 ?0 v cc , v ee = 7.0v (tape) (speed) mode = norm - norm 100hz 1khz 10khz playback equalizer amplifier distortion input level [dbv] line amplifier frequency response (pass mode) output response [db] frequency [hz] line amplifier thd + n output level [db] meter rectification output characteristics rectification voltage [v] frequency [hz] 100 1 0.1 20 1k 10k +10db 0db ?0db ?0db ?0db ?0db v cc , v ee = 7.0v 0db = ?dbv (nr rec out) +13db level meter output characteristics (rec, pb mode) meter output voltage [v] input level [db] 1.0 ?0 ?0 ?0 0 0.01 5.0 0.1 v cc , v ee = 7.0v dv cc = +5.0v pb mode: 0db = ?dbv (line out) rec mode: 0db = ?dbv (nr rec out) f = 1khz
?34 CXA1878Q 20 10 0 ?0 ?0 ?0 10k 100 1k v cc , v ee = 7.0v 0db = ?1dbv ams mode bs mode 34 35 36 37 38 5.0 6.0 7.0 8.0 0 0.5 1.0 1.5 2.0 ?.0 ?.9 ?.8 ?.7 ?.6 ?.5 ?.4 bias n bias c bias m v cc , v ee = 7.0v a.m.s/b.s mode frequency response input level [db] frequency [hz] bias sw load characteristics output voltage [v] output current [ma] supply voltage vs. current consumption current consumption [ma] supply voltage [v]
?35 CXA1878Q dolby b type nr encode boost 100 frequency [hz] 10 8 6 4 2 0 ? 1k 10k encode boost [db] v cc , v ee = 7v dolby level 400hz, ?dbm ?0db ?5db ?0db ?5db ?0db ?5db ?0db frequency [hz] 12 8 4 0 ? 100 1k 10k encode boost [db] v cc , v ee = 7v dolby level 400hz, ?dbm ?0db ?5db ?5db ?0db ?5db ?0db ?5db ?0db ?db ?0db ?5db ?0db 20 16 dolby c type nr encode boost 0db (dolby level) ?db 0db (dolby level) t.h.d + n [%] 1 0.1 0.01 output level [db] ? 0 4 8 12 16 20 v cc , v ee = 7.0v 0db = ?dbm (nr rec out, nr off) encode mode 100hz 1khz 10khz dolby nr off total harmonic distortion ? 0 4 8 12 16 20 0.01 0.1 1 output level [db] t.h.d + n [%] v cc , v ee = 7.0v 0db = ?dbm (nr rec out, nr off) encode mode 100hz 1khz 10khz dolby b type nr total harmonic distortion 0.1 0.01 t.h.d + n [%] 1 ? 0 4 8 12 16 20 output level [db] v cc , v ee = 7.0v 0db = ?dbm (nr rec out, nr off) encode mode dolby c type nr total harmonic distortion 100hz 1khz 10khz
?36 CXA1878Q package outline unit: mm sony code eiaj code jedec code 23.9??.4 20.0?.1 0.4 ?0.1 + 0.15 14.00.1 1 19 20 32 33 51 52 64 0.15 ?0.05 + 0.1 2.75 ?0.15 16.3 0.1 ?0.05 + 0.2 0.8 0.2 m 0.12 0.15 +?.4 17.9??.4 +0.4 + 0.35 64pin qfp(plastic) qfp?4p?01 qfp064??420 package material lead treatment lead material package mass epoxy resin solder/palladium 42/copper alloy package structure plating 1.5g 1.0

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