I wonder if anyone can help. Im running an ARM dev board (Teensy4.1) to effectively become another MCU programmer. Being ARM, the GPIO are 3.3v, the target MCU PCB is 5v, so far ive been converting the logic level which has worked all good (for logic).
However I have found a requirement where I need to pulse a line, but it appears the target is taking more current than I can output. So in this instance a direct connection will result (via inspection on scope) with a voltage drop of nearly 2v when I try to send the signal with the target powered ON. it requires logic but behaves more like an analog line.
I have tried various things such as PNP transistors, P channel MOSFET and even a infineon smart controller. With the transistors i am getting distorted line high/low signals on the rising and falling edges, and the trickiest part is that I need to change the state High/Low within a maximum 40ms time period. So far the infineon smart controller has worked closest to optimum, but the on/off time is around 250ms so I cant use that.
Does anyone know of the best circuit to create this high side switch (fyi it must be high side as the ground connections are shared), requirements:
- gate/ control signal can be either 3.3v or 5v
- output clean 5v high, 0v low (or very close)
- pulsing with clean rising and falling edges (this is the one where I cant seem to sort using FETs / transistors)
-pulse high/low duration of 40ms max
any guidance is much appreciated, ive attempted most references from similar questions online, in those cases people are turning on dc motors or similar, and I would have that solved - but a more accurate and fast high side switch required.