Tool/software:
Hello there,
We have implemented the TPS1H100-Q1 chip version A in our design and during testing we encountered an issue.
The voltage input (VS pin) is 12V and the load we are using is a POS (Point of Sale) that draws a maximum current of 2Amps.
The ST (fault) pin is hooked up to a 3.3V Microcontroller and Input (enable) pin is controlled with the 3.3V Microcontroller and a Raspberry Pi, using a NOR Gate configuration.
When the POS is attached to our circuit and when setting the Input pin in HIGH state with a Microcontroller to enable the output we experience a Fault detection for around 50 to 500us, hence triggering an interruption on our Microcontroller.
yellow is the 12V output, blue is the ST fault pin.
We have the same issue when turning off output:
We have measured the 12V voltage at the input and output and we did not see any voltage spikes and the line remains constant.
We have found out that we do not have that issue with a sufficient small resistor as a load.
With a resistor as a load (to keep ST fault pin HIGH) while the output is ON and then plugging in the POS in parallel with the resistor we have the same fault detection.
Here is our schematic:
Could you please review our schematic for any potential issues which might be triggering a false fault detection or anything that could help us solve the issue?
Thank you
Regards,
Jon
