ir2103 HO does not work for low side

Thread Starter


Joined Sep 22, 2023
i want to drive P channel and N channel mosfet with ir2103.i use LO to drive P channel mosfet and it work fine,but HO does not work and has zero value on output.input logic is 3.3v and i have tested different LIN and HIN zero and 3.3 volt and LO works fine but HO is zero continuously .
shunt resistor is 1 ohm and load is just about 200 mA.
it has no frequency,just for switch on or off load.

what is problem?


Joined Sep 17, 2013
Welcome to AAC!
Why are you using HighOut to drive the low-side FET and LowOut to drive the high-side FET?
Do you really need Q8?
The mystery shunt resistor that you mention is not in your schematic.


Joined Aug 7, 2020
Actually the IR devices can be used like that, in theory, but why? When there are plenty of dual low-side drivers that can do the job properly such as TC4426/7/8 depending whether you want inverting, noninverting or one of each.