1 dem-dai1737/1739 features l socket accepts either pcm1737 or pcm1739 l on-board low-pass filters for left and right channels l easy configuration using on-board switches and jumpers l 96khz digital audio receiver accepts s/pdif and optical inputs l demonstration software for pro- gramming and reading the pcm1737s internal registers (requires a pc running microsoft windows ? 3.1, 95, or 98) l centronics connector for interfacing to a pc parallel port (required for the demonstration software) ? 1999 burr-brown corporation li-541 printed in u.s.a. november, 1999 block diagram instruction manual dem-dai1737 dem-dai1739 international airport industrial park ? mailing address: po box 11400, tucson, az 85734 ? street address: 6730 s. tucson blvd., tucson, az 85706 ? tel: (520) 746-1111 twx: 910-952-1111 ? internet: http://www.burr-brown.com/ ? cable: bbrcorp ? telex: 066-6491 ? fax: (520) 889-1510 ? immediate p roduct info: (800) 548-6132 description the dem-dai1737/1739 is a complete evaluation platform for the pcm1737 and pcm1739 24-bit ste- reo, audio digital-to-analog converters. all necessary connectors are provided for interfacing to audio test systems and commerical audio equipment. evaluation fixture digital audio receiver and logic sw1 - sw3 format control coax opt pcm1737 pcm1739 d/a converter jp001 scki clko bck bck (left jus) lrck data l/r ch 2nd-order lpf opa2134 v out l v out r gnd gnd ml mc mdi rst mdo gnd +v dd 3.3v regulator sw101 v cc v cc av cc ?v cc + l power supply requirements: +5v, +15v, and C15v l connector for optional external +3.3v power supply
2 dem-dai1737/1739 sw001 sw002 sw003 receiver output data format l l l 16- to 24-bit, left-justified l h l 16- to 24-bit, i 2 s h l h 16-bit, right-justified (or standard) l h h 18-bit, right-justified (or standard) table i. digital audio receiver configuration. hardware description power supplies the evaluation fixture requires three power supplies for operating the pcm1737 or pcm1739, digital support cir- cuitry, and the low pass filter op amp. these supplies are connected to vertical header cn051. v cc is the +5v power supply. it is used to power the analog sections of the pcm1737 or pcm1739, as well as the digital audio receiver (u002) and associated logic (u003 and u004). av cc + and av cc C are used to power the burr-brown opa2134 dual op amp (u201), which performs the d/a output low pass filter function. avcc+ may be set from +5v to +18v, while av cc C may be set from C5v to C18v. in addition to the three required external power supplies, a +3.3v supply is required for the pcm1737 or pcm1739. the +3.3v supply is typically derived from v cc using an on-board linear regulator, burr-browns reg1117-3.3 (u051). a jumper must be installed at cn053 to connect the regulator output to the pcm1737 or pcm1739. a connector (cn052) is provided for connection to an optional external +3.3v power supply. when using cn052, the jumper at cn053 must be removed in order to disable the regulator output. analog outputs the left and right audio outputs are available at rca jacks cn201 and cn202 respectively. the outputs are taken from the low pass filter, which has a gain of 2. the low-pass filter may be configured for one of two cut-off frequencies: 54khz or 108khz. for f C3db = 54khz, jumpers jp201 through jp206 must all be installed. for f C3db = 108khz, jumpers jp201 through jp206 must all be removed. zero flag outputs the zero flags for the left and right channels are brought out on connector cn101. zfgl is the zero flag for the left channel, while zfgr is the zero flag for the right channel. the zero flags are normally low, but will switch to a high state when 1024 consecutive sample periods (or lrck periods) have passed with all 0s data on the din (or data) input. these flags may be used to control external mute circuitry, or as status indicators for a microcontroller, audio dsp/decoder, or other digitally controlled functions. digital audio interface a digital audio receiver (u002) is provided for easy connec- tion to s/pdif and optical signal sources, including audio test systems (audio precision, rhode & schwarz) and com- mercial audio equipment (cd and dvd players). the re- ceiver can operate up to a 96khz word rate with 24-bit data. switches sw001 through sw003 are used to set the receiver output data format, as shown in table i. table ii shows the jumper configuration for jp001 when using the digital audio receiver. 16-bit 18-bit 16- to 24-bit 16- to 24-bit jp001 right-justified right-justified i 2 s left-justified jumper format format format format scki o o o o bck (left jus) nc nc nc o bck o o o o lrck o o o o data o o o o clko x x x x gnd o o o o o = install jumper; nc = remove jumper, x = don't care. table ii. jp001 jumper configuration for use with the digital audio receiver. switch sw004 is a normally open, momentary contact pushbutton switch used to reset the digital audio receiver when necessary. in addition to the digital audio receiver, the evaluation fixture may be interfaced to an external audio dsp, decoder, or alternative signal source through connector jp001 using standard ribbon cable connections. dip switch configurationpcm1737 dip switch sw101 is used primarily for configuration of the pcm1739. when using the pcm1737, the switches should be set as follows: filt = l mute = l ibit = l 1739 = l rstb = h dem0 = h dem1 = h form = h rstb may be used to force an external reset of the pcm1737. this is done by setting rstb = l, followed by setting rstb = h.
3 dem-dai1737/1739 the information provided herein is believed to be reliable; however, burr-brown assumes no responsibility for inaccuracies or o missions. burr-brown assumes no responsibility for the use of this information, and all use of such information shall be entirely at the users own risk. pr ices and specifications are subject to change without notice. no patent rights or licenses to any of the circuits described herein are implied or granted to any third party. burr-brown does not authorize or warrant any burr-brown product for use in life support devices and/or systems. dip switch configurationpcm1739 when using the pcm1739, the 1739 switch of sw101 must be set to the h position. sw101 is used to set the configuration of the pcm1739s mode controls. table iii shows the available settings for sw101. pc parallel port/host connector the evaluation fixture includes a centronics connector, cn102, which is used to connect to a pc parallel (or printer) port, or an alternative host controller. this connector is utilized to access the serial control port of the pcm1737. the serial control port is used to program and read the pcm1737s internal registers. a standard printer cable is used to connect cn102 of the evaluation fixture to a pc parallel port. schematics figures 1 through 4 provide schematics for the dem- dai1737/1739. pcb layout figures 4 through 6 provide pcb plots for the dem- dai1737/1739. sw101 switch(s) setting function filt l 8x oversampling (used for f s up to 96khz h 4x oversampling (used for f s > 96khz) mute l mute disabled, normal operation h mute enabled, outputs forced to bipolar zero ibit l 24-bit audio data word length h 16-bit audio data word length rstb l reset mode, outputs forced to bipolar zero h normal operation dem0 digital de-emphasis dem1 dem1 dem0 selection l l de-emphasis disabled l h 32khz de-emphasis filter h l 44.1khz de-emphasis filter h h 48khz de-emphasis filter form l standard, right-justified data format hi 2 s data format table iii. pcm1739 mode control settings.
4 dem-dai1737/1739 figure 1. dac, digital audio interface, and i/o connections. u101 cs8414 v cc 13 12 10 8 9 5 4 2 1 12 13 6 3 11 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 verf ca/f2 sdata erf m1 m0 va+ agnd filt mck m2 m3 sel cbl c cd/f1 cc/f0 cb/e2 ca/e1 c0/e0 vd+ dgnd rxp rxn fsync sck cs12/fck u 19 1 20 2 21 3 22 4 23 5 24 6 25 7 26 8 27 9 28 10 29 11 30 12 31 13 32 14 33 15 34 16 35 17 36 18 r 004 470 w r 003 47k w c 012 10 f sw004 pushsw u003 hc14 u004 hc32 d001 1s1500 sw001 m0 sw002 m1 sw003 m2 + +v cc m2 m1 m0 m3 jp2 v dd 1739 ibit cn101 zfgr zfgl 1739 sw101 1 2 3 4 ibit v out l v cc v dd v out r notes: for pcm1739, these pins become: (1) ibit (2) filt (3) mute (4) nc (5) dem0 (6) dem1 (7) form m2 m3 m1 m0 v cc c 007 10 f + c 11 10 f c 103 10 f c 104 10 f + c 11 10 f + + + c 008 0.1 f v cc c 005 10 f c 006 0.1 f 1 3 + v cc c 003 10 f + 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 ml (7) mc (6) mdi (5) mdo (4) zeror zerol rstb nc (3) nc (2) v cc l gndl extl v out l v cc a mdo mdi mc ml rstb rstb ml mc mdi mdo lrck data bclk clko sclk v ss v dd test1 test2 (1) v cc r gndr extr v out r gnda data lrck bck bck (left-justified) scki c 103 10 f c 104 10 f + + + r 002 470 w r 001 75 w cn001 c 009 0.068 f c 108 0.1 f c 108 10 f v cc 2 4 5 6 c 002 0.01 f c 001 0.01 f torx176 34 c 004 0.1 f u001 coax u003 hc14 u102 vhc244 cn102 ml mc mdi rst mdo 2 3 4 5 6 7 8 9 1a1 2y4 1a2 2y3 1a3 2y2 1a4 2y1 oe2 1y1 2a4 1y2 2a3 1y3 2a2 1y4 2a1 oe1 18 17 16 15 14 13 12 11 1 19 cn002 data scki pcm1737 bck (left-justified) bck lrck verf erf v dd r a 101 47k w x 123 4
5 dem-dai1737/1739 figure 2. dac low-pass filters. v out l v out r c 203 1200pf c 205 1200pf r 201 8.2k w c 201 10 f/16v c 209 120pf jp201 jp203 1/2 opa2134a jp205 2 3 1 4 r 205 15k w r 203 1k w r 207 100 w r 208 100 w cn201 rca + c 207 120pf c 211 10 f/16v c 212 10 f/16v u201 av cc + av cc c 204 1200pf c 206 1200pf r 202 8.2k w c 202 10 f/16v c 210 120pf jp202 jp204 1/2 opa2134a jp206 6 5 7 8 r 206 15k w r 204 1k w cn202 rca + c 208 120pf u201 + +
6 dem-dai1737/1739 figure 4. silk screen (top side). figure 3. power supply connections. c 89 100 f c 90 0.1 f c 93 100 f c 92 100 f + ++ gnd cn1 v cc av cc ?v cc + av cc + av cc gnd gnd v cc gnd 54321 v cc u051 reg1117-3.3 23 1 gnd in out gnd cn052 12 cn053 v dd c 109 0.1 f v dd c 056 10 f 3.3v + + c 055 0.1 f gnd for u102 c 010 0.1 f v cc c 011 0.1 f for u003, u004 gnd v dd
7 dem-dai1737/1739 figure 5. top side layer. figure 6. bottom side layer.
8 dem-dai1737/1739 pcm1737 demonstration software software is provided with the dem-dai1737/1739 to allow programming of the pcm1737s internal registers. the software will operate on computers running microsoft win- dows 3.1, 95, or 98. the demo software requires that the pc printer port be connected to cn102 of the dem-dai1737/ 1739 using a standard printer cable. installation the demo software is distributed on a 3.5-inch floppy disk. there is a single folder on the disk, named dem1737. this folder contains the application and all support files. to install the software on your computer, first create a new folder on your hard drive with an appropriate name (e.g., dem1737, pcm1737, etc). then open the dem1737 folder on the installation floppy and copy all of the files in it to your new folder. open the configuration settings file named dem1737 with a text editor, such as notepad or wordpad. when the file is opened, find the following line: pcmifadr = &h378 the &h378 indicates the printer port address that the demo software will use to communicate with the dem-dai1737/ 1739. this address must be set to &h378, &h278, or &h3bc. most pcs use &h378 as the default printer port address. if your printer port is not located at &h378, edit the address to match your computers port address. using the demo software double click on the application file named dem1737. a window will appear on your screen, as shown in figure 7 there are two menus near the top of the window, named execute and window. the execute menu includes three selections: initialize, re- set, and exit. selecting initialize will instruct the program to write all of the pcm1737s internal registers with the default values. selecting reset will instruct the program to re-write the pcm1737s internal registers with the data currently selected in the application windows. selecting exit will close the application. the window menu includes four selections: attenuation, operational control, function control, and register read. the following sections provide an explanation of each window. hold and pass each window has a button near the top. its labeled either hold or pass. the setting is toggled by clicking on this button. when set to hold, the user can change the settings in a window but they will not be written to the register(s) until the ok button (which appears at the bottom left corner of the window) is pressed. when set to pass, changes made within a window are immediately written to the correspond- ing register(s). attenuation window the attenuation window is used to set the digital attenua- tion registers internal to the pcm1737 and is shown in figure 8. there is an attenuator for both the left and right output channels, and each attenuator has its own indepen- dent register to control its level. in the attenuation window, there is a slider for each attenuator register. use the slider handle or the arrows at each end of the slider to adjust the attenuation level. the left and right arrow keys on the keyboard can also be used to adjust the level. just below each slider is a status display showing the current register setting (in decimal) and the corresponding attenuation level in decibels (db) relative to the input signal level. the attenuation window also includes the atld, or at- tenuation load control. when atld is set to off, the attenuator function is disabled. when atld is set to load, changes in slider settings will take effect immediately (if the window is set to pass), or when the ok button is clicked (if the window is set to hold). figure 7. startup window. figure 8. attenuation window.
9 dem-dai1737/1739 the attenuation window also includes the atts, or attenu- ation speed control. atts is used to set the rate at which the attenuator is stepped when a level change is made. the speed is either 2/f s or 4/f s , where f s is the sampling fre- quency. operational control window the operational control window is shown in figure 9. this window is used to set the following functions: ? soft mute (mute lch, mute rch): on or off ? dac operation (dac lch, dac rch): on or off ? zero detect mute (izd): on or off ? digital de-emphasis (dem): off, 32khz, 44.1khz, or 48khz for more information regarding these functions, refer to the pcm1737 data sheet. function control window the function control window is shown in figure 10. this window is used to set the following functions: ? dac oversampling rate (over): 64fs or 128fs ? digital interpolation filter rate (k192): 8x or 4x ? digital filter low pass response (flt): sharp, slow 1, or slow 2 ? clko enable (clke): on or off ? clko rate (clkd): f sclk (normal) or f sclk / 2 (1/2 xti) ? audio data format (format) for more information regarding these functions, refer to the pcm1737 data sheet. register read window the pcm1737 serial control interface includes register read capability. the register read window allows the user to read the value of all pcm1737 registers by pressing a single button. the window is shown in figure 11. the register read window provides a means to check for proper commu- nications between the pc printer port and the dem-dai1737/ 1739, by allowing the user to verify register write opera- tions. figure 9. operational window. figure 10. function control window. figure 11. register read window.
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