MLX10803_06 Datasheet, PDF (6/25 Pages) List of Unclassifed Manufacturers – High power LED driver

IC specification MLX10803
High power LED driver
resistor should be placed as close as possible to IREF2 pin and stripe from IREF1 pin to NTC resistor should be
shielded by GND stripe.
The schematic diagram under Figure 1 is used in applications where the LED is controlled by external control
electronics. A PWM with a frequency between 30Hz..5kHz can be applied to the VS/PWM pin in order to
dim the light output. This frequency is limited by the time needed for recharging the coil and monoflop time selected
by the resistor connected to ROSC as well as by the IC settling time after POR. This function can be used to
achieve different light outputs or also be used in a temperature down regulation.
It is recommended to have the PWM frequency at least 5-10 times lower than the selected driver switching
frequency.
Diode is placed between DRVGATE and VS/PWM IC pins serves as discharger of gate of FET transistor. Thus,
having switched off IC at VS/PWM voltage=0 DRVGATE turns to Z-state. Charge that was stored in gate capacitor
runs down to VS/PWM module pin via the diode.
The minimum schematic diagram under Figure 2 is sufficient for all applications with a constant light output.
We also recommend to compare with our other circuits in the MLX108xx family and study these application notes
for suitable solutions.
3901010803
Rev 024
Page 6/25
Data Sheet
7/DEC/06