iC-WK, iC-WKL

2.4 V CW LASER DIODE DRIVER

Rev D1, Page 2/8

DESCRIPTION

The iC-WK/L device is a driver for laser diodes in con-

tinuous wave operation which requires only four ex-

ternal components. The wide power supply range of

2.4 to 6 V and the integrated reverse battery protec-

tion allow for battery operation with a minimum of two

cells. A reversed battery connection destroys neither

the iC nor the laser diode.

The iC includes integrated circuitry protecting against

destruction by ESD, excessive temperature and over-

current and a soft start which regulates the power

and protects the laser diode when the power supply

is switched on. The iC also filters the laser diode

power supply for transients.

The power supply is regulated and adapted to the

laser diode used by an external resistor at MDA. The

monitor current acts as a reference and is regulated

independent of the influence of temperature and sup-

ply voltage (range: 10 µA to 2.5 mA). The capacitor at

CI determines the control time constants and start-up

time.

A second monitor input, pin MDK, allows the driver to

be used for other types of laser diode configuration;

alternatively, it can be used as an analogue modula-

tion input (DC to a few kHz).

In the event of failure, such as overcurrent in the laser

path with a lack of feedback, for example, a quick

power lockout is activated. The shutdown continues

until power is reapplied, permitting a restart. The

strain on power packs and batteries is relieved and

the laser class is retained even in the event of a dis-

turbance.

iC-WK offers additional protection by means of spike

detection at pin MDA. Should spikes or oscillation

occur at pin MDA the power lockout is activated.

PACKAGES SO8, MSOP8 to JEDEC

PIN CONFIGURATION SO8

(top view)

1

2

3

4

8

7

6

5

GND

MDK

AGND

MDA

LDA

CI

VCC

LDK

PIN CONFIGURATION MSOP8

(top view)

1

GND

CI

AGND

MDK

LDK

LDA

VCC

MDA

PIN FUNCTIONS

No. Name Function

1 GND

Ground

2 CI

Capacitance for Power Control

3 AGND Reference Ground for CI, RM

4 MDK

Monitor Input 2

(MD Cathode, Modulation)

5 MDA

APC Setup,

Monitor Input 1 (MD Anode)

6 VCC

+2.4 to +6 V Supply Voltage

7 LDA

Laser Supply (LD Anode)

8 LDK

Driver Output (LD Cathode)

Do not short-circuit pins AGND and GND, for this may

deteriorate the precision of the regulator and interfere

with the soft-start!