Dear Sirs,
I would like to connect two TPS1H100 in series for a functional safety application.
Rough schematic
- 24V - Drain from the first high side switch
- Source from first high side switch to drain from second high side switch
- Source from the second high side switch to the load
- The digital interface is controlled by two independent MCUs.
I want to apply test pulses to both switches (100us ... 1ms). I have an independend feedback system. This way I can make sure that one switch is always present to cut the current.
The digital signals for the control remain present at both switches (even if the supply is gone).
In the datasheet I found no detailed information about the startup of the switch, slewrate at the drain (power supply), ... .
Which problems do I have to expect at the switches?
I have concerns with the following scenarios
- The first switch generates test pulse -> how does the second switch react?
- Can I ensure that the pulses do not become longer? -> I interrrupt the power supply of the second switch.
- What voltages may be present at the digital interface if the supply voltage is not present?
- can latch up effects occur?
- Do you see other issues I haven't seen?
Kind regards
Dominique
