CWD-01-V2-D Analog Technology, Inc., CWD-01-V2-D Datasheet - Page 2

• Manufacturer Part Number: CWD-01-V2-D
• Description: Constant Current Cw Laser Driver
• Manufacturer: Analog Technology, Inc.

SPECIFICATIONS
Table 2 Characteristics (T
OPERATION PRINCIPLE
The block diagram of the controller is shown in Figure 3.
The shut down control circuit accepts signals from 3 sources:
5 50 E. Weddell Drive, Suit e 4, Sunnyvale, CA 94 08 9, U. S. A. Tel.: (4 08 ) 7 47 -9 76 0, Fax: [phone] , W eb: w w w .analogt echnologies.com
 Copyrights 2000 – 2009, Analog Technologies, Inc. All Rights Reserved. Updated on 9/15/2009
Laser driver efficiency
Maximum output current
Current output noise
Stability
Laser current control signal level
Control accuracy
Laser current indication signal level
Indication accuracy
Output reference voltage
Power supply voltage range
Operating case temperature
10
11
12
9
Analog Technologies
Parameter
PGND
PGND
LDA
VPS
2.5VR
SDN
LIS
LIGD
LIO
ambient
= 25°C)
1
4
5
8
6
Analog Output
Power Ground
Power Ground
Power Input
3.3 ~ 5.5
−20 ~ 85
2.5V
voltage
reference
0 ~ 2.5
0 ~ 2.5
Value
±0.2
±0.2
Laser current
control indication
0.05
≥90
100
2.5
EA
2
Current
measurement
Figure 3 Block Diagram
ppm/°C
except that this pin is of an analog output and Pin 2 is of a digital output.
Laser diode anode. Connect it to the anode of the laser diode.
Power ground pin. Connect this pin directly to the cathode of the laser
diode.
Power ground pin. Connect this pin directly to power supply return pass.
Power supply voltage. The driver will work from VPS = 3.3V to 5.5V.
Unit
°C
%
%
%
%
A
V
V
V
V
Soft start
& thermal
shutdown
Constant
current
driver
Constant Current CW Laser Driver
external shut down, over current and over temperature signals.
When one of these signals is activated, the controller is shut
down. Only when all these 3 signals go up, the soft start circuit
starts enabling the low noise driver.
It comes with a laser diode status indication circuit. When
LDGD pin is high, >2V, the control loop is working properly.
When this pin is low, <0.3V, the laser diode is bad, or there is a
short or open circuit at the laser diode.
It comes also with a laser current control indication circuit.
When this pin is stabilized and the value is between 0.2V and
1.8V, the output voltage to the laser, Pin 9 LDA, will be 4.8V
to 0V linearly, the laser current is stabilized, and the control
loop is stable. This pin has a similar function as Pin 2 LDGD,
except that this pin is of an analog output and Pin 2 is of a
digital output.
The high stability low noise 2.5V voltage reference can be used
for setting the output current, and also be used for the ADCs
and/or DACs.
An internal soft start circuit allows a slow start up and a quick
shut down.
The current measurement circuit monitors the output current
and shuts down the controller upon detecting the output current
exceeds the pre-set value.
Over current
protection
Laser
diode
status
indication
10
2
9
LDGD
PGND
LDA
Laser
diode
CWD-01-V2-D
2