iC-WKN 15 V CW LASER DIODE DRIVER Rev B1, Page 1/9 FEATURES APPLICATIONS CW operation up to 300 mA from 2.4 to 15 V supply voltage Blue laser diodes LD modules Rapid soft start after power-on typical within 70 s Optimised for N-type laser diodes Simple output power adjustment via an external resistor (APC) Power control loop accuracy better than 1.5 % with changes in temperature, supply voltage and load current Integrated reverse polarity protection for the iC and laser diode Strong suppression of transients with very small external capacitors integrated yback path Permanent shutdown with excessive temperature and overcurrent (i.e. if the laser diode is damaged or the feedback PACKAGES current path fails) Two feedback inputs permit all current LD types to be used (N/P/M congurations) Modulation via the feedback inputs is possible Wide monitor current range from 2.5 A to 6.25 mA Pin compatible to iC-WK and iC-WKL (SO8 package) SO8tp DFN10 4 mm x 4 mm (on request) BLOCK DIAGRAM 6 7 VCC +2.4..+15 V LDA CVCC CLDA ..1 uF..47 nF.. TRANSIENT 4 PROTECTION MDK MD LD 5 MDA + iCWKN VREF 0.5 V 2 CI 1 D 8 LDK NQ R CM RM CI 0.08..200 k W 47 pF ..100 nF.. OVERCURRENT FEEDBACK MON. OVERTEMP. 1 3 GND AGND GND suitable laser diode configurations: N, P, M MD LD LD MD MD LD Copyright 2004 iC-Haus iC-WKN 15 V CW LASER DIODE DRIVER Rev B1, Page 2/9 DESCRIPTION iC-WKN is a driver for laser diodes in continuous A second monitor input, pin MDK, allows the driver to wave operation with laser currents of up to 300 mA, be used for other types of laser diode conguration which requires only four external components. The alternatively, it can be used as an analog modulation wide power supply range of up to 15 V allows for op- input (DC to a few kHz). eration of blue laser diodes. In the event of failure, such as overcurrent in the laser The iC includes integrated circuitry protecting against path due to a lack of feedback, for example, a quick destruction by ESD, excessive temperature and over- power lockout is activated. The shutdown persists current plus a soft start of the regulator to protect the until power is reapplied, permitting a restart. The laser diode when the power supply is switched on. strain on power packs and batteries is relieved and The iC also lters the laser diode power supply for the laser class is retained even in the event of a dis- transients. turbance. The regulator is adapted to the laser diode by an ex- iC-WKN offers additional protection by means of ternal resistor at MDA. The monitor current acts as spike detection at pin MDA. Should spikes or oscilla- a reference and is regulated independent of the in- tion occur at pin MDA the power lockout is activated uence of temperature and supply voltage (range: after a certain time-out. 2.5 A to 6.25 mA). The capacitor at CI determines the control time constants and start-up time.