AMLDP-Z Datasheet, PDF (5/18 Pages) AIMTEC – Up to 1000mA | LED Driver

Output Current Adjustment by PWM Control:
Driving VADJ Directly
Series AMLDP-Z
Up to 1000mA | LED Driver
A Pulse Width Modulated (PWM) signal with a duty cycle of DPWM can be applied directly to VADJ pin as shown below.
The output current is given by:
Ioutnom = Iout x DPWM [for 0.01<DPWM<1]
PWM VADJ
1.25V
0V
GND
AMLDP-Z
-Vin
+Vout
1^st LED
1
-Vout
Last LED
1
Driving VADJ Via Open Collector Transistor
The VADJ can also be driven via an open collector transistor as shown below.
The diode and resistor serve to suppress any possible high amplitude negative voltage spikes to the VADJ input resulting
from the collector to emitter capacitance of the transistor. Any negative voltage spikes will cause errors in output current
and/or unstable driver operation.
+Vout
PWM
1.25V
0V
VADJ
10K
AMLDP-Z
-Vin
-Vout
1^st LED
1
Last LED
1
1
GND
Driving the VADJ from a Microcontroller
The VADJ can be driven from an open drain output of a microcontroller as shown below. The diode and resistor serve to
suppress any possible high amplitude negative voltage spikes to the VADJ input resulting from the drain to source
capacitance of the FET. Any negative voltage spikes will cause errors in output current and/or unstable driver operation.
MCU
VADJ
10K
1
AMLDP-Z
-Vin
GND
+Vout
-Vout
1^st LED
1
Last LED
1
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