ChipFind - документация

Электронный компонент: T0810

Скачать:  PDF   ZIP
T0810
Rev. A5, 08-Aug-01
1 (9)
3-Channel Laser Driver with RF Osc. and APC Amplifier
Description
The T0810 is a laser diode driver for the operation of a
grounded laser diode for CD-RW drives. It includes three
channels for three different optical power levels which
are controlled by a separate IC. The read channel gener-
ates a continuous output level whereas the channels 2 and
3 are provided as write channels with very fast switching
speeds. Write current pulses are enabled when a `low'
signal is applied to the NE Pins. All channels are summed
together at the IOUT Pin. Each channel can contribute up
to 150 mA to the total output current of up to 200 mA. A
total gain of 400 mA is provided between each reference
current input and output. Although the reference inputs
are current inputs, voltage control is possible by using
external resistors.
An on-chip RF oscillator is provided to reduce laser mode
hopping noise during read mode. Frequency and swing
can be set by two external resistors. Oscillation is enabled
by a `high' at the ENOSC Pin. Complete output current
and oscillator switch-off is achieved by a `low' at the
ENABLE input.
The T0810 also includes a fast settling APC (Adaptive
Power Control) transimpedance amplifier. It is provided
to interface between the front end monitor photo diode
and the ALPC (Adaptive Laser Diode Power Controller)
circuit.
Electrostatic sensitive device.
Observe precautions for handling.
Features
D Current-controlled output current source with 3 input
channels
D Low-power consumption
D Output current per channel to 150 mA
D Total output current to 200 mA
D Rise time 1.0 ns / fall time 1.1 ns
D On-chip RF oscillator
D Control of frequency and swing by use of 2 external
resistors
D Oscillator frequency range from 200MHz to 500 MHz
D Oscillator swing to 100 mA
D Fast settling APC amplifier
D Single 5-V power supply
D Common enable / disable input
D TTL/CMOS control signals
D Small SSO16 package
Application
D CD-RW drives
D Writable optical drives
Block Diagram
APC
Channel 3
Channel 2
I3
NE3
I2
NE2
Read
channel
RF oscillator
IR
ENOSC
ENABLE
IOUT
VREF
PDIN
VOUT
RF
RS
Figure 1. Block diagram
T0810
Rev. A5, 08-Aug-01
2 (9)
Ordering Information
Extended Type Number
Package
Remarks
T0810-TCQ
SSO16
Taped and reeled
Pin Description
Pin
Symbol
Function
1
VOUT
APC amplifier output
2
VREF
Reference voltage input
3
IR
Inp. current, bias voltage approx. GND
4
RF
External resistor to GND sets
oscillator frequency
5
I2
Inp. current, bias voltage approx. GND
6
I3
Inp. current, bias voltage approx. GND
7
NE2
Digital control of channel 2
(low active)
8
NE3
Digital control of channel 3
(low active)
9
VCC
+ 5 V power supply
10
ENOSC
Enables RF oscillator (high active)
11
ENABLE
Enables output current (high active)
12
RS
External resistor to GND sets
oscillator swing
13
GND
Ground
14
IOUT
Output current source for laser diode
15
VCC
+ 5 V power supply
16
PDIN
Photo diode input
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
IR
RF
I2
I3
NE2
NE3
VOUT
VREF
IOUT
GND
RS
ENABLE
ENOSC
VCC
PDIN
VCC
T0810
Figure 2. Pinning SSO16
Absolute Maximum Ratings
Parameter
Symbol
Value
Unit
Supply voltage
V
CC
0.5 to +6.0
V
Input voltage at IR, I2, I3
V
IN1
0.5 to + 0.5
V
Input voltage at NE2, NE3, ENOSC
V
IN2
0.5 to V
CC
+ 0.5
V
Output voltage
V
OUT
0.5 to V
CC
1
V
Power dissipation
P
MAX
1
1)
W
Junction temperature
T
J
150
_C
Storage temperature range
T
STG
65 to +125
_C
1)
R
thJA
80 K/W
T0810
Rev. A5, 08-Aug-01
3 (9)
Thermal Resistance
Parameter
Symbol
Value
Unit
Junction ambient
R
thJA
150
K/W
Recommended Operating Conditions
Parameter
Symbol
Value
Unit
Supply voltage range
VCC
4.5 to 5.5
V
Input current
I
IR
/I
I2
/I
I3
< 0.4
mA
External resistor to GND to set oscillator frequency
RF
> 3
k
External resistor to GND to set oscillator swing
RS
> 100
Operating temperature range
T
amb
0 to +70
_C
Electrical Characteristics : General
V
CC
= 5 V, T
amb
=25
_C, ENABLE = High, NE2 = NE3 = High, ENOSC = Low, unless otherwise specified
Parameter
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
Power supply
Supply current, power down
ENABLE = Low,
NE2 = NE3 = Low
ICC
PD
0.2
0.4
mA
Supply current, read mode,
Oscillator disabled
I
IR
= I
I2
= I
I3
= 125
A
ICC
R1
90
107
mA
Supply current, read mode,
Oscillator enabled
I
IR
= I
I2
= I
I3
= 125
A,
ENOSC = High, RS = 560
,
RF = 6.8 k
ICC
R2
100
118
mA
Supply current, write mode
I
IR
= I
I2
= I
I3
= 125
A,
NE2 = NE3 = Low
ICC
W
190
220
mA
Supply current, input off
I
IR
= I
I2
= I
I3
= 0
A
ICC
off
15
20
mA
Digital inputs
NE2/NE3 low voltage
VNE
LO
1.3
V
NE2/NE3 high voltage
VNE
HI
2.0
V
ENABLE low voltage
VEN
LO
0.5
V
ENABLE high voltage
VEN
HI
3.0
V
ENOSC low voltage
VEO
LO
0.5
V
ENOSC high voltage
VEO
HI
2.0
V
Current at digital inputs
NE2/NE3 low current
NE = 0 V
INE
LO
300
A
NE2/NE3 high current
NE = 5 V
INE
HI
800
A
ENABLE low current
ENABLE = 0 V
IEN
LO
150
A
ENABLE high current
ENABLE = 5 V
IEN
HI
100
A
ENOSC low current
ENOSC = 0 V
IEO
LO
100
A
ENOSC high current
ENOSC = 5 V
IEO
HI
800
A
T0810
Rev. A5, 08-Aug-01
4 (9)
Electrical Characteristics : Laser Amplifier
V
CC
= 5 V, T
amb
= 25
_C, ENABLE = High, unless otherwise specified
Parameter
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
Best fit current gain
Any channel
1)
GAIN
400
mA/mA
Best fit current offset
Any channel
1)
IOS
8
+4
mA
Output current linearity
Any channel
1)
ILIN
3
+3
%
Input current range
Input is sinking
IDAC
0
0.4
mA
Output current per channel
Output is sourcing
I
OUTR
150
mA
Total output current
I
OUT
200
mA
I
OUT
series resistance
I
OUT
= 180 mA total
R
OUT
to V
CC
Rail
R
OUT
8
I
IN
input impedance
R
IN
is to GND
R
IN
1200
2000
2500
NE threshold
Temperature stabilized
VTH
1.68
V
Output off current 1
ENABLE = Low
IOFF
1
0.5
mA
Output off current 2
NE2 = NE3 = High,
I
IR
= 0, I
I2
= I
I3
= 125
A
IOFF
2
0.7
mA
Output off current 3
NE2 = NE3 = Low,
I
IR
= I
I2
= I
I3
= 0
A
IOFF
3
5
mA
I
OUT
supply sensitivity,
read mode
I
OUT
= 40 mA,
V
CC
= 5 V
10%, read only
VSE
R
4
1
%/V
I
OUT
supply sensitivity,
write mode
I
OUT
= 80 mA, 40 mA read +
40 mA write, V
CC
= 5 V
10%
VSE
W
6
0
%/V
I
OUT
current output noise
I
OUT
= 40 mA, ENOSC = Low
INO
O
3
nA/rtHz
I
OUT
temperature sensitivity,
read mode
I
OUT
= 40 mA, read only
TSE
R
100
ppm/
C
I
OUT
temperature sensitivity,
write mode
I
OUT
= 80 mA, 40 mA read +
40 mA write
TSE
W
100
ppm/
C
1)
Linearity of the amplifier is calculated using a best fit method at three operating points of
I
OUT
at 20 mA, 40 mA, and 60 mA. I
OUT
= (I
IN
GAIN) + I
OS
T0810
Rev. A5, 08-Aug-01
5 (9)
Electrical Characteristics :
Laser Current Amplifier Outputs AC Performance
VCC = + 5 V, I
OUT
= 40 mA DC with 40 mA pulse, T
A
= 25
C unless otherwise specified
Parameter
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
Write rise time
I
OUT
= 40 mA (read) + 40 mA
(10% to 90%)
1)
t
RISE
1.0
3.0
ns
Write fall time
I
OUT
= 40 mA (read) + 40 mA
(10% to 90%)
1)
t
FALL
1.4
3.0
ns
Output current overshoot
I
OUT
= 40 mA (read) + 40 mA
1)
OS
5
%
I
OUT
ON propagation delay
NE 50% HighLow to I
OUT
at
50% of final value
t
ON
2.0
ns
I
OFF
OFF propagation delay
NE 50% LowHigh to I
OUT
at
50% of final value
t
OFF
2.0
ns
Disable time
ENABLE 50% HighLow to
I
OUT
at 50% of final value
t
DIS
10
ns
Enable time
ENABLE 50% LowHigh to
I
OUT
at 50% of final value
t
EN
50
ns
Amplifier bandwidth
I
OUT
= 50 mA, all channels,
3dB value
BW
LCA
16
MHz
Oscillator
Oscillator frequency
RF = 4.3 k
F
OSC
380
470
560
MHz
Osc. temperature coefficient
RF = 4.3 k
TC
OSC
150
ppm/
C
Disable time oscillator
ENOSC 50% HighLow to I
OUT
at 50% of final value
T
DISO
4
ns
Enable time oscillator
ENOSC 50% LowHigh to I
OUT
at 50% of final value
T
ENO
2
ns
1)
Load resistor at IOUT: 10
// 39
+ 50
(see test circuit)
Electrical Characteristics : APC Amplifier
V
CC
= 5 V, T
A
= 25
C, R
LOAD
= 2 k
to V
REF
unless otherwise specified
Parameter
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
Bandwidth
G = 1, Cload = 22 pF
BW
APC
200
MHz
Slew rate
G = 1, V
OUT
= 1 V to 3 V
SR
80
V/
s
Setting time
To 0.1%, V
OUT
= 1 V to 3 V
t
s
50
ns
Open loop voltage gain
V
OUT
= 1 V to 3 V
Avol
60
dB
Offset voltage
V
REF
= 3 V
V
OS
5
+5
mV
Input bias current
V
REF
= 3 V
1.5
A
Common mode input range
CMRR > = 54 dB
CMIR
1
V
CC
1.5
V
Common mode rejection ratio
V
CM
= 0.5 V to 3.0 V
CMRR
60
dB
Input impedance
R
IN
20
k
Input capacitance
Pin 16 (PDIN)
C
IN
2
pF
Output voltage swing
R
L
= 2 k
to V
REF
V
OUT
1
V
CC
1.5
V