RESET

(Active Low,

TTL compatible

VDD

GND

LDC1

LDC1

LDC2

LDC2

PWR GND

(for LD VS)

PWR GND

(for LD VS)

VSET 1

VSET 2

(Impedance:

2kΩ per driver,

1kΩ when

paralleled)

GND (forVSET)

VS

LD

VDD

SAFETY INFORMATION

SAFE OPERATING AREA — DO NOT EXCEED

INTERNAL POWER DISSIPATION LIMITS

Before attempting to operate the FL500 driver, it is imperative

that you first determine that the unit will operate within the

Safe Operating Area (SOA). Operating outside of the SOA

may damage the laser and the FL500. Operating outside of

the SOA will void the warranty.

To determine if the FL500 driver will be operating in the

safe range in your application, consult the instructions for

calculating the Safe Operating Area online:

www.teamwavelength.com/support/design-tools/soa-ld-calculator/

SOA charts are included in this datasheet for quick reference

(

page 11), but we recommend you use the online tools

instead.

To ensure safe operaTion of The fL500 Driver, iT

is imperaTive ThaT you DeTermine if The uniT is going

To be operaTing wiThin The inTernaL heaT DissipaTion

safe operaTing area (soa).

If you have any questions about the Safe Operating Area

calculator, call the factory for free and prompt technical

assistance.

PREVENT DAMAGE FROM ELECTROSTATIC

DISCHARGE

Before proceeding, it is critical that you take precautions to

prevent electrostatic discharge (ESD) damage to the driver

and your laser. ESD damage can result from improper

handling of sensitive electronics, and is easily preventable

with simple precautions.

For more information regarding ESD, see Application Note

AN-LDTC06: Basics: Electrostatic Discharge (ESD).

We recommend that you always observe ESD precautions

when handing the FL500 driver and your laser diode.

!

THEORY OF OPERATION

The FL500 driver is a controlled current source: it delivers

the current commanded by the setpoint. The current source

continually monitors the actual output current, compares it to

the setpoint, and adjusts the current if there is a difference

between the two signals.

It may be useful to remember that you do not directly set the

driver current setpoint; instead, you adjust a voltage signal

that represents the output current. The voltage and output

current are related by a transfer function that varies by driver

capacity. The setpoint voltage is adjusted with an external

input.

As current is driven through the load, there is a voltage drop

across the load because of the impedance. As the current

increases, the voltage drop may increase to the point that it

reaches the Compliance Voltage limit of the current source.

Once that occurs, the current source is no longer able to

increase the current driven to the load even if you increase

the setpoint.

Figure 6 shows the block diagram of the FL500.

The FL500 driver includes features that help protect your

laser and make the driver more versatile in a wide array of

applications: handheld devices, airborne applications, and

spectroscopy systems.

Figure 6. FL500 Block Diagram

© 2025

www.teamWavelength.com

7

FL500 LASER DIODE DRIVER