STCS1A

nmohammad · ‎2025-07-11

Hi I am using STCS1APUR to drive 10LEDS IR, (MTSM5116MT2-BK), circuit below

current should be 1A as of f/b resistance, enable gets turn on as sson as the STM32 MCU comes up, supplying a 3.3VDC PWM though the MCU

issue:

the voltage drop across the led is only 0.6VDC, and they are dim, when checked the current , its less than 0.04A across the LEDS

when there is no trigger there is a 4VDC deop cmpared to the +VLED(24VDC)

i read the sheep twice and unable to figure out the issue

on time is 250msec

Andrew Neil · ‎2025-07-11

@nmohammad wrote:
the voltage drop across the led is only 0.6VDC

How do you measure that?

LED forward voltages are normally about 1.6V or more ...

@nmohammad wrote:
on time is 250msec

and what is the period?

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