Other Parts Discussed in Thread: LM5069, BQ76925
Hi, I am working on high-side load switch and need help with choosing appropriate IC. Here are my requirements:
- I want to use two N-MOSFETs in back-to-back configuration (normal working current is going to be 5A or so)
- 3.3V level compatible, high-impedancy ENABLE input
- quiescent supply current when disabled (0V on ENABLE) must be less than 50uA
- supply current when enabled might be few mA
- really fast MOSFET discharge when disabling using the ENABLE input
- the input voltage would be 22V max.
- I'm going to use two circuits like this with connected outputs (similar to supply ORing, but controlled from MCU)
I've found LM5060 which meets almost all the requirements except the MOSFET discharge time - it's got only 2.2mA sink current to discharge the gate. And I think it's not fast enough for two 30nC gates - the power loss while short-circuit on the output would damage the MOSFETs, even with some small series inductor to limit di/dt. (and I don't want to use 0.5mH just because of small sink current...) Also, one of the power supplies will be Li-Ion akupack and short-circuit for too long may be dangerous/unhealthy.
What device/circuit would you reccomend me as a solution?
Many thanks.
Tomas
