NJW4710 -1- v e r.2 4ch laser diode driver for blue laser diode general description package outline NJW4710 is a laser diode driver for the operation of a grounded blue laser diode. it is suited to drive a blue laser diode, because it is operated by split power supply. it includes 4 channels current amplifiers for 4 different optical power levels. an on-chip rf oscillator is provided to reduce laser mode noise during read mode. oscillation frequency and oscillation amplitude are defined by two external resistors feature operating voltage vcc1=4.5v to 5.5v, vcc2=8.0 to 10.0v internal oscillator circuit 200mhz to 500mhz rise time / fall time 0.8ns typ. maximum output current 250ma typ. bi-cmos technology package outline ssop24-e1 pin configuration block diagram 1 12 13 24 1:gnd 2:iinr 3:gnd 4:iin2 5:rfreq 6:iin3 7:iin4 8:vcc1 9:outen2 10:outen3 11:outen4 12:gnd 13:gnd 14:vcc2 15:vcc2 16:oscen 17:enable 18:ramp 19:gnd 20:iout 21:iout 22:vcc2 23:vcc2 24:gnd vcc1 i inr gnd iout oscen enable bias ramp osc rfreq outen2 outen3 ou t en 4 vcc2 i in2 i in3 i in4 ch-r ch-2 ch-3 ch-4 NJW4710ve1
NJW4710 - 2 - v e r.2 absolute maximum ratings (ta=25 c) parameter symbol ratings unit supply voltage 1 vcc1 6.0 v supply voltage 2 vcc2 11.0 v input voltage vin 6.0 v power dissipation p d 700 mw operating temperature range topr -40 to +85 c storage temperature range tstg -40 to +150 c recommended opearating condition (ta=25 c) parameter symbol test condition min. typ. max. unit operating voltage1 vopr1 4.5 5.0 5.5 v operating voltage2 vopr2 8.0 9.0 10.0 v electrical characteristics dc characteristics (vcc1=5v,vcc2=9v,enable=h,outen=h,oscen=l h:5v,l:gnd, ta=25 c) parameter symbol test condition min. typ. max. unit supply current 1 i cc 1 enable 0.5v - 0 10 ma supply current 2 i cc 2 iinr/2/3/4=0ua,rfeq=open,ramp=open - 19 24 ma supply current 3 i cc 3 oscen=h, rfreq=3.6k ? ,ramp=5k ? - 33 40 ma supply current 4 i cc 4 outen=h, iin/2/3/4=500ua - 62 76 ma supply current 5 i cc 5 outen=h, iinr/2/3/4=500ua - 120 140 ma high level input voltage vih outen, oscen 2 - - v low level input voltage vil outen, oscen - - 1.3 v enable high level input voltage evih enable 3 - - v enable low level input voltage evil enable - - 1.5 v outen high level input current diih outen=5v 0 - 10 ua outen low level input current diil outen=0v -300 - 0 ua enable high level input current eiih enable=5v 0 - 500 ua enable low level input current eiil enable=0v -10 - 0 ua oscen high level input current oiih oscen=5v 0 - 450 ua oscen low level input current oiil oscen=0v -10 - 0 ua v + 1 shut-down voltage vshut 3.40 - 3.75 v
NJW4710 - 3 - v e r.2 laser amplifier dc characteristics (vcc1=5v, vcc2=9v enable=h,h:5v,l:gnd,ta=25 c) parameter symbol test condition min. typ. max. unit current gain gi chr/2/3/4, vo=5v *1 80 110 140 ma /ma output offset current ios chr/2/3/4, vo=5v *1 -5 - +5 ma output current linearity iiin chr/2/3/4, vo=5v *1 -3 - +3 % input current range 1 iin1 chr 0 - 2 ma input current range 2 iin2 ch2/3/4 0 - 3.5 ma maximum output current 1 iomax1 chr 50 100 - ma maximum output current 2 iomax2 ch2/3/4 100 200 - ma iout series resintance ro iout=200ma - 10 - ? input resistance 1 rin1 chr 1.62 2.5 3.38 k ? input resistance 2 rin2 ch2/3/4 325 500 675 ? output off current 1 ioff1 enable=l - - 5 ma output off current 2 ioff2 outen=h, total for all channels - - 5 ma output off current 3 ioff2 outen=l, i in =0ua,total for all channels - - 5 ma output current supply sensitivity 1 vc1 v + 1=5v 0.5v, v + 2=9v 0.5v,iout=40ma -1 2 4 %/v output current supply sensitivity 2 vc2 v + 1=5v 0.5v, v + 2=9v 0.5v,iout=80ma -1 2 4 %/v output current temperature sensitivity 1 tc1 iout=40ma,chr only - 400 - ppm/ c output current temperature sensitivity 2 tc2 iout=80ma,40maread+40ma,write - 400 - ppm/ c *1 the amplifier linearity is calculated using best fit method at three points. the output currents chosen 20 ma, 40ma,and, 60ma.the transfer function for iout is defined as follows: iout =(i in +gain)+ios laser amplifier ac characteristics (vcc1=5v, vcc2=9v,iout=40ma dc with 40ma pulse, ta=25 c) parameter symbol test condition min. typ. max. unit rise time tr iout= 40ma(read)+40ma(10-90%) - 0.8 - ns fall time tf iout= 40ma(read)+40ma(10-90%) - 0.8 - ns over shoot os - 5 - % iout on time ton outen 50% h l to iout 50% - 1 - ns iout off time toff outen 50% h l to iout 50% - 1 - ns disable time tdis enable 50%h l to iout 50% - 20 - ns enable time ten enable 50%l h to iout 50%, - 150 - ns hfm disable time tdiso oscen h l to iout 50% - 10 - ns hfm enable time teno oscen l h to iout 50%, - 10 - ns oscillator frequency fosc rfreq=3.6k ? 280 350 420 mhz oscillator temperature coefficient tc o s c rfreq=3.6k ? - -300 - ppm/ c output current noise ino iout=40ma,chr only - 0.9 - na/ hz
NJW4710 - 4 - v e r.2 iout control enable outen2 outen3 outen4 iout l/open x x x off h h/open h/open h/open iout= i inr *120 h l h/open h/open iout=(i inr +i in2 )*120 h l l h/open iout=(i inr +i in2 +i in3 )*120 h l l l iout=(i inr +i in2 +i in3 +i in4 )*120 oscillator control enable oscen outen2 outen3 outen4 oscillator l/open x x x x off h l/open x x x off h h x x x on timing diagram ten ton toff tdis tf tr ton toff ton toff tf tr tf tr iout ou ten 4 ou ten 3 ou ten 2 enable
NJW4710 - 5 - v e r.2 test circuit 2k 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 2k 2k 2k 5.0k 5v 9v 1u 10u iinr 0.1u 0.1u 0.1u iin2 iin3 iin4 1u 10u ld gnd iinr gnd iin2 rfreq iin3 iin4 vcc1 outen2 outen3 outen4 gnd gnd vcc2 vc c 2 oscen enable ramp gnd iout iout vcc 2 vcc 2 gnd 0.1u 3.6k ttl/cmos ttl/cmos ttl/cmos ttl/cmos cmos + + 0.1u 0.1u 0.1u 0.1u + + + +
NJW4710 - 6 - v e r.2 terminal explanation pin no. pin name function 1 3 12 13 19 24 gnd gnd 2 iinr input of constant current output circuit for read channel. output current value is set up by input current or input voltage. 4 iin2 input of constant current output circuit for erase, write channel. output current value is setup by input current or input voltage. 5 rfreq set up for oscillator frequency. resistance is connected to gnd and a setup in optional frequency. 6 iin3 input of constant current output circuit for erase, write channel. output current value is setup by input current or input voltage. 7 iin4 input of constant current output circuit for erase, write channel. output current value is setup by input current or input voltage. 8 vcc1 supply voltage for amplifier circuit: vcc1=5v 9 outen2 output current control for channel 2 high(<2v) or open: non-output low(>1.3v): output 10 outen3 output current control for channel 3 high(<2v) or open: non-output low(>1.3v): output 11 outen4 output current control for channel 4 high(<2v) or open: non-output low(>1.3v): output 14 15 22 23 vcc2 supply voltage for output circuit: vcc2=9v 16 oscen output control for oscillator. high(<2v): oscillation superposition low(>1.3v) or open: non-output 17 enable control for ic. high(<3v): output low(>1.5v) or open: non-output 18 ranp setup for oscillation superposition. resistance is connected to gnd and a setup in optional oscillation superposition. 20 21 iout output current terminal. please connect cathode common type laser or floating type laser to gnd. *please set up low voltage not less than gnd-0.3v ,and high voltage of each control terminal (enable, outen 2, 3, and 4, oscen) does not exceed vcc1+0.3v.
NJW4710 -7- v e r.2 iin rex rin vin rex rin iin application set up for operating voltage recommended operating voltage of NJW4710 is vcc=5v,vcc=9v. vcc2=9v is set up in consideration of the forward voltage [vf] (6v max.) of a blue laser diode. therefore, in the case of a red laser diode or blue laser diode with low forward voltage, please set up the power supply voltage of vcc2 above the following. operating voltage of vcc2 = forward voltage(max) of laser diode + 3v set up for output current current gains of each channels of all are 120ma/ma typ. set up of the output current value in current input and voltage input is below. in the case of current input please input current to ic. output current is the following. iout=120*iin [ma] in the case of current input output current is the following. iout=120*vin/(rex+rin) [ma] output current can be set up by rex=0ohm. however, to reduce input noise, please add a capacitor between rex and gnd. (refer to test circuit). rin(input resistance of ic) is ch-r:2.5kohm,ch-2/3/4:500ohm. set up for internal oscillator NJW4710 contained in the oscillator for the light power change reduction by the return light noise of laser. the quality of reading improves by operating oscillator and output it. in this oscillator, oscillation frequency can be set up by connect resistance with a rfreq(5pin) between gnd. moreover, set up of the amount of oscillation superposition can be performed by connect resistance with a ramp(18pin) between gnd. oscillation frequency is 150mhz to 600mhz. it can adjust to 10mapp to 100mapp (refer to typcal characteristics) in the amount of high frequency superposition. output of this oscillator is push-pull circuit. therefore, the output of the oscillator for high frequency superposition is overlapped focusing on the output current value set up in the constant current output circuit. fig.2 in the case of current input fig.3 in the case of voltage input
NJW4710 - 8 - v e r.2 0 100 200 300 400 500 600 700 800 0 20 40 60 80 100 120 140 160 024681012 frequency/amplitude vs ramp rfreq=3.8k freqency (mhz) amplitude (mapp) ramp (k ohm) frequency amplitude oscillation frequency/amplitude vs. resistance for set up frequency oscillation frequency/amplitude vs. resistance for set up overlap 0 100 200 300 400 500 600 700 800 0 20 40 60 80 100 120 140 160 0246810121416 frequency/amplitude vs. rfreq ramp=5k frequency (mhz) amplitude (mapp) rfreq (k ohm) frequency amplitude
NJW4710 - 9 - v e r.2 package outline ssop24-e1 0. 1 5 0. 1 0 0. 1 2 m 1. 1 5 0. 1 0. 1 0 0. 0 5 0. 5 0. 2 0~10 -0.05 +0.1 0. 2 2 -0.05 +0.1 0. 6 5 0. 375typ 112 13 24 7. 9 0. 2 5. 6 0. 2 7. 6 0. 2 [caution] the specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. the application circuits in this databook are described only to show representative usages of the product and not intended for the g uarantee or p ermission of an y ri g ht
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