PIN DESCRIPTION
Table 1. Pin Descriptions
PIN
LABEL
PIN #
NAME
PIN DESCRIPTION
VDD
1
Control Electronics Power
Power supply input for the FL500’s internal control electronics. Supply range
input for this pin is +3 to +12 Volts DC. It is compatible with Li+ batteries.
GND
2
Control Electronics Ground
Return path for control electronics. Connect ground for V
DD
power supply
here. Do not use for high current ground return.
RESET
3
Enable / RESET Control
TTL compatible. LO = laser diode current on
FLOAT or HI = laser diode current attenuated to ~10 µA
(~20 µA if drivers are paralleled to produce 500 mA)
VSET1
4
Setpoint for LDC1 control
2 kΩ input impedance. 0 to 2 V range. There is no internal clamping, so
higher voltage here will produce more current through the laser diode.
Not recommended above 2 V.
GND
5
Ground for setpoint inputs
Low Current, Low Noise ground for use with VSET1 & VSET2.
VSET2
6
Setpoint for LDC2 control
2 kΩ input impedance. 0 to 2 V range. There is no internal clamping, so
higher voltage here will produce more current through the laser diode.
Not recommended above 2 V.
LDC2
LDC2
7
8
Laser Diode Cathode,
Driver 2
Tie to laser diode cathode for individual drive operation (250 mA max).
Tie to LDC1 for parallel operation up to 500 mA.
Tie to pin 8 (also LDC2) if laser diode current exceeds 125 mA. Actual pin
capacity is greater, but higher current produces offsets and higher noise.
PGND
PGND
9
10
Power Ground for VS
connection (VS powers
laser diode)
Use for ground connection of VS power supply.
Tie to pin 10 (also PGND) if laser diode current exceeds 125 mA.
LDC1
LDC1
11
12
Laser Diode Cathode,
Driver 1
Tie to laser diode cathode for individual drive operation (250 mA max).
Tie to LDC2 for parallel operation up to 500 mA.
Tie to pin 12 (also LDC1) if laser diode current exceeds 125 mA. Actual pin
capacity is greater, but higher current produces offsets and higher noise.
© 2020
4
FL500 LASER DIODE DRIVER
