NJW4702
3ch Laser Diode Driver
s
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.
s
FEATURES
q
Operating Voltage
4.5V to 5.5V
q
On-chip RF Oscillator
200MHz to 500MHz
q
Rise-time/Fall-time
1.0ns typ.
q
Maximum Output Current 250mA typ.
q
Bi-CMOS Technology
q
Package Outline
PCSP16(3.5mm 0.65mm pitch)
s
BLOCK DIAGRAM
s
PACKAGE OUTLINE
NJW4702SE8
IOUT
12
GND
11
RAMP
10
ENABLE
9
H:ON
VCC2 13
H:ON
L:ON
L:ON
8 OSCEN
GND 14
OSC
BIAS
7 VCC1
GND 15
6 GND
VINR 16
5 OUTEN3
1
RFREQ
2
VIN2
3
VIN3
4
OUTEN2
Ver.1
-1-
NJW4702
s
ABSOLUTE MAXUIMUM RATING
(Ta=25°C)
PARAMETERS
SYMBOL
RATINGS
+
Supply Voltage
V
6.0
Power Dissipation
P
D
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
s
RECOMMENDED OPERATING CONDITION
(Ta=25°C)
PARAMETERS
Operating Voltage
SYMBOL
Vopr
TEST CONDITION
MIN.
4.5
TYP.
5.0
MAX.
5.5
UNIT
V
UNIT
V
mW
°C
°C
s
ELECTRICAL CHARACTERISTICS
qDC
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
Shutdown Voltage
SYMBOL
I
CC
1
I
CC
2
I
CC
3
I
CC
4
I
CC
5
VIH
VIL
IIH
IIL
Vshut
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
MIN.
-
-
-
-
-
3.5
-
-
-100
3.4
TYP.
0
5
55
20
80
-
-
-
-
-
MAX.
10
7
75
30
110
-
1.5
100
-
3.7
UNIT
µA
mA
mA
mA
mA
V
V
µA
µA
V
VINR=0.8V,VIN2/3=0.3V,
OUTEN=L,OSCEN=H,Vcc at Icc≤1mA
qLaser
Amp 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
Current Convert Gain 1
Current Convert Gain 2
Output Offset Current
Output Current Linearity
Input Voltage Range
Maximum Output Current 1
Maximum Output Current 2
SYMBOL
Gi1
Gi2
Ios
IIin
VrefR
CHR *1
CH2/3 *1
CHR/2/3 *1
CHR/2/3 *1
CHR/2/3
TEST CONDITION
MIN.
35
80
-2
-3
0
100
200
-
6
-
-
-
-
-
-
TYP.
50
120
-
-
-
150
250
6
9
-
-
10
10
-800
-800
MAX.
65
160
+8
+3
5
-
-
-
12
1.0
3.0
15
15
-
-
UNIT
mA/V
mA/V
mA
%
V
mA
mA
Ω
kΩ
mA
mA
%/V
%/V
ppm/°C
ppm/°C
Iomax1 CHR
Iomax2 CH2/3
Ro
Rin
Ioff1
Ioff2
Vc1
Vc2
TC1
TC2
Iout Series Resistance
Input Resistance
Output OFF Current 1
Output OFF Current 2
Supply Voltage Alternation of
Output Current 1
Supply Voltage Alternation of
Output Current
2
OUTEN=H,VINR/2/3=0V,Total for All Channels
OUTEN=L,VINR/2/3=0V,Total for All Channels
Vcc=4.5 to 5.5V,VINR=0.8V,CHR only
Vcc=4.5 to 5.5V,OUTEN2or3=L,VINR=0.8V,
VIN2/3=0.3V,CHR+CH2or3
VINR=0.8V,CHR only
OUTEN2or3=L,VINR=0.8V,VIN2/3=0.3V,
CHR+CH2or3
Temperature coefficient of
Output Current 1
Temperature coefficient 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
qLaser
Amp AC CHARACTERISTICS
(Vcc=5.0,Ta=25°C unless otherwise specified)
PARAMETERS
Enable Time
Disable Time
ON Time
OFF Time
Rise Time
Fall Time
Over Shoot
Oscillator Frequency
Oscillator Temperature
Coefficient
Output Current Noise
sIout
Control
ENABLE
L/OPEN
H
H
H
H
s
Oscillator Control
ENABLE
L/OPEN
H
H
s
Timing Diaglam
OSCEN
X
L/OPEN
H
OUTEN2
X
X
X
OUTEN3
X
X
X
OSCILLATOR
OFF
OFF
ON
OUTEN2
X
H/OPEN
L
H/OPEN
L
OUTEN3
X
H/OPEN
H/OPEN
L
L
OFF
Iout=VINR*Gi1
Iout=VINR*Gi1+VIN2*Gi2
Iout=(VINR+VIN3)*Gi1
Iout=(VIN2+VIN3)*Gi1+VIN2*Gi2
Iout
SYMBOL
Ten
Tdis
Ton
Toff
Tr
Toff
OS
fOSC
TEST CONDITION
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
MIN.
-
-
-
-
-
-
-
380
-
-
TYP. MAX.
150
20
1
1
1
1
5
470
-300
3.5
-
-
-
-
-
-
-
560
-
-
UNIT
ns
ns
ns
ns
ns
ns
%
MHz
ppm/°C
nA/√Hz
TcOSC Rfreq=3.6kΩ
Ino
Iout=40mA,CHR only
ENABLE
OUTEN2
OUTEN3
Ten
Ton
Toff
Ton
Toff
Tdis
Iout
Tr
Tf
Tr
Tf
Ver.1
-3-
NJW4702
s
TEST CIRCUIT
GND
3.6kohm
VINR
RFREQ
VIN2
VIN3
OUTEN2
OUTEN3
GND
GND
VCC2
IOUT
GND
1kohm
RAMP
ENABLE
OSCEN
VCC1
5V
oscilloscope
Current Probe
s
APPLICATION CIRCUIT
Vcc
GND
VINR
DAC
RFREQ
VIN2
VIN3
OUTEN2
OUTEN3
CMOS
GND
GND
VCC
2
IOUT
GND
RAMP
ENABLE
OSCEN
VCC1
Vcc
LaserDiode
PhotoDiode
[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-
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