NJW4702 3ch Laser Diode Driver ■GENERAL DESCRIPTION NJW4702 is a laser diode driver for the operation of a grounded laser diode for CD-R and CD-RW drivers. It includes three channels current amplifiers for three different optical power levels. Reference inputs are voltage input, and voltage control is possible without external resistors. 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. ■PACKAGE OUTLINE NJW4702SE8 ■FEATURES ● Operating Voltage 4.5V to 5.5V ● On-chip RF Oscillator 200MHz to 500MHz ● Rise-time/Fall-time 1.0ns typ. ● Maximum Output Current 250mA typ. ● Bi-CMOS Technology ● Package Outline PCSP16(3.5mm 0.65mm pitch) ■BLOCK DIAGRAM IOUT GND RAMP ENABLE 12 11 10 9 H:ON 8 OSCEN VCC2 13 H:ON L:ON L:ON OSC GND 14 7 VCC1 BIAS GND 15 6 GND VINR 16 Ver.1 5 OUTEN3 1 2 3 4 RFREQ VIN2 VIN3 OUTEN2 -1- NJW4702 ■ABSOLUTE MAXUIMUM RATING (Ta=25°C) PARAMETERS SYMBOL RATINGS + Supply Voltage V 6.0 Power Dissipation PD 860 * Operating Temperature Range Topr -40 to +85 Storage Temperature Range Tstg -40 to +125 *EIA/JEDEC STANDARD Test Board(76.2x114.3x1.6mm,4layers,FR-4)mounting UNIT V mW °C °C ■RECOMMENDED OPERATING CONDITION (Ta=25°C) PARAMETERS Operating Voltage SYMBOL TEST CONDITION Vopr MIN. TYP. MAX. UNIT 4.5 5.0 5.5 V ■ELECTRICAL CHARACTERISTICS ●DC CHARACTERISTICS(Vcc=5.0V,ENABLE=H,OUTEN=H,OSCEN=L, H:5V,L:GND,2V to Iout, Ta=25°C unless otherwise specified) PARAMETERS Supply Current 1 Supply Current 2 Supply Current 3 Supply Current 4 Supply Current 5 High Level Input Voltage Low level Input Voltage High Level Input Current Low Level Input Current SYMBOL ICC1 ICC2 ICC3 ICC4 ICC5 VIH VIL IIH IIL TEST CONDITION ENABLE≤0.5V VINR/2/3=0V OSCEN=H,RAMP=1kΩ,RFREQ=3.6kΩ VINR=0V,VIN2=0.3V,VIN3=0.3V VINR=0.8V,VIN2/3=0.3V VINR=0.8V,VIN2/3=0.3V, OUTEN=L,OSCEN=H,Vcc at Icc≤1mA ●Laser Amp DC CHARACTERISTICS Shutdown Voltage Vshut MIN. TYP. MAX. UNIT 3.5 -100 0 5 55 20 80 - 10 7 75 30 110 1.5 100 - µA mA mA mA mA V V µA µA 3.4 - 3.7 V (Vcc=5.0V,ENABLE=H,OUTEN=H,OSCEN=L, H:5V,L:GND,2V to Iout, Ta=25°C unless otherwise specified) PARAMETERS SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Current Convert Gain 1 Gi1 CHR *1 35 50 65 mA/V Current Convert Gain 2 Gi2 CH2/3 *1 80 120 160 mA/V Output Offset Current Ios CHR/2/3 *1 -2 - +8 mA IIin VrefR CHR/2/3 *1 CHR/2/3 -3 0 - +3 5 % V Output Current Linearity Input Voltage Range Maximum Output Current 1 Iomax1 CHR 100 150 - mA Maximum Output Current 2 Iomax2 CH2/3 200 250 - mA 6 9 - 12 1.0 Ω kΩ mA Iout Series Resistance Input Resistance Output OFF Current 1 Ro Rin Ioff1 OUTEN=H,VINR/2/3=0V,Total for All Channels 6 - Output OFF Current 2 Ioff2 OUTEN=L,VINR/2/3=0V,Total for All Channels - - 3.0 mA Vc1 Vcc=4.5 to 5.5V,VINR=0.8V,CHR only - 10 15 %/V Vc2 Vcc=4.5 to 5.5V,OUTEN2or3=L,VINR=0.8V, VIN2/3=0.3V,CHR+CH2or3 - 10 15 %/V Temperature coefficient of Output Current 1 TC1 VINR=0.8V,CHR only - -800 - ppm/°C Temperature coefficient of Output Current 2 TC2 OUTEN2or3=L,VINR=0.8V,VIN2/3=0.3V, CHR+CH2or3 - -800 - ppm/°C Supply Voltage Alternation of Output Current 1 Supply Voltage Alternation of Output Current 2 *1 The amplifier linearity is calculated using best fit method at three points. The output currents chosen 20mA, 40mA,and, 60mA.The transfer function for Iout is defined as follows: Iout =Gi*VIN+Ios Ver.1 -2- NJW4702 ●Laser Amp AC CHARACTERISTICS(Vcc=5.0,Ta=25°C unless otherwise specified) PARAMETERS SYMBOL Enable Time Disable Time Ten Tdis ON Time Ton OFF Time Toff Rise Time Fall Time Over Shoot Oscillator Frequency Oscillator Temperature Coefficient Output Current Noise Tr Toff OS fOSC TEST CONDITION MIN. ENABLE L→H 50% to Iout 50%, Iout=40mA ENABLE H→L 50% to Iout 50%, Iout=40mA OUTEN H→L 50% to Iout 50%, Iout=40mA+40mA OUTEN L→H 50% to Iout 50%, Iout=40mA+40mA CHR+CH2/3,Iout 10-90%,Iout=40mA+40mA CHR+CH2/3,Iout 10-90%,Iout=40mA+40mA Rfreq=3.6kΩ UNIT - 150 20 - ns ns - 1 - ns - 1 - ns 380 1 1 5 470 560 ns ns % MHz - -300 - ppm/°C - 3.5 - nA/√Hz TcOSC Rfreq=3.6kΩ Ino TYP. MAX. Iout=40mA,CHR only ■Iout Control ENABLE OUTEN2 OUTEN3 Iout L/OPEN H X H/OPEN X H/OPEN OFF Iout=VINR*Gi1 H L H/OPEN Iout=VINR*Gi1+VIN2*Gi2 H H/OPEN L Iout=(VINR+VIN3)*Gi1 H L L Iout=(VIN2+VIN3)*Gi1+VIN2*Gi2 ■Oscillator Control ENABLE OSCEN OUTEN2 OUTEN3 OSCILLATOR L/OPEN H H X L/OPEN H X X X X X X OFF OFF ON ■Timing Diaglam ENABLE OUTEN2 Ton OUTEN3 Toff Toff Ton Tdis Ten Iout Tr Ver.1 Tf Tr Tf -3- NJW4702 ■TEST CIRCUIT 3.6kohm GND GND VINR VCC2 RFREQ IOUT VIN2 GND Current Probe oscilloscope 1kohm VIN3 RAMP OUTEN2 OUTEN3 GND ENABLE OSCEN VCC1 5V ■APPLICATION CIRCUIT Vcc DAC CMOS GND GND VINR VCC 2 IOUT RFREQ VIN2 GND VIN3 RAMP OUTEN2 ENABLE OUTEN3 OSCEN GND VCC1 PhotoDiode LaserDiode Vcc [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 guarantee or permission of any right including the industrial rights. Ver.1 -4-