Switch IC

Greedy.

Some of the CMOS-based gate drivers do some of that, but I don't think many (or any) will go to the voltage extremes you want, or give you the fault indication.

Let us know if you find anything. I think a circuit with two or three chips, at a minimum, are in your future.

Yup. The switch is easy, the fault protection and indication takes parts. ...Jim Thompson

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wonder if something like an A4952 + an inverter would work

-Lasse

Good idea! There's probably an easy way to trick a full-H regulator into being a simple static switch. ...Jim Thompson

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looks like it is as simple a tying the sense pin to ground and an inverter between in1 and in2

-Lasse

Micrel makes a nice high side switch, sans fault indication.

I can't seem to find it , but there was a 24v mosfet high side switch. I can only find the 13v MC2514 on the website.

Perhaps one of their High side Mosfet switches and a mosfet? Those can provide fault indication.

Cheers

Many Class D amplifier chips can do the ground/power protection and voltage requirements. No sure about the switching speed.

Regards Werner Dahn

Class D ICs use bootstrapping for driver power; so they can't work with 100% duty cycle. Designing separate supplies for upper and lower drivers is not much better then building the whole thing from discretes.

Vladimir Vassilevsky DSP and Mixed Signal Consultant

Thanks. I looked at the high/low side switches, they are too slow.

Vladimir Vassilevsky DSP and Mixed Signal Consultant

wonder if something like an A4952 + an inverter would work

This is almost what needed. Unfortunately, it is too inteligent and specialized. A need to suppress that excessive functionality complicates interface to this IC.

Vladimir Vassilevsky DSP and Mixed Signal Consultant

haven't tried but, looking at the truth table it looks like you just need an inverter so in1 and in2 are inverse, and Vsense tied to ground so it never starts chopping

-Lasse

Vladimir Vassilevsky wrote:

A little hacky but, something like this? I know Jim will love, no emitter R's and all :)

Version 4 SHEET 1 880 680 WIRE -96 0 -96 -16 WIRE 304 16 176 16 WIRE 416 16 416 0 WIRE 416 16 304 16 WIRE 176 32 176 16 WIRE 416 48 416 16 WIRE -96 96 -96 80 WIRE 80 96 0 96 WIRE 304 96 256 96 WIRE 352 96 304 96 WIRE 80 144 80 96 WIRE 176 144 176 112 WIRE 176 144 128 144 WIRE 192 144 176 144 WIRE 0 160 0 96 WIRE -96 192 -96 176 WIRE 416 192 416 144 WIRE 416 192 400 192 WIRE 416 224 416 192 WIRE 496 224 416 224 WIRE 176 240 176 224 WIRE 0 256 0 240 WIRE 80 256 80 224 WIRE 256 256 256 192 WIRE 256 256 80 256 WIRE 256 272 256 256 WIRE 416 288 416 224 WIRE 128 320 128 144 WIRE 192 320 128 320 WIRE 320 336 272 336 WIRE 352 336 320 336 WIRE 320 368 320 336 WIRE 320 368 256 368 WIRE 416 400 416 384 WIRE 416 400 368 400 WIRE 368 448 368 400 WIRE 368 448 256 448 FLAG 496 304 0 FLAG -96 80 0 FLAG -96 -16 P+ FLAG -96 192 P- FLAG 416 0 P+ FLAG 416 400 P- FLAG 0 256 0 FLAG 176 240 0 SYMBOL pnp 352 144 M180 SYMATTR InstName Q1 SYMATTR Value 2N4403 SYMBOL npn 352 288 R0 SYMATTR InstName Q2 SYMATTR Value 2N2222 SYMBOL res 480 208 R0 SYMATTR InstName R1 SYMATTR Value 47 SYMBOL voltage -96 -16 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value 24 SYMBOL voltage -96 80 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value 24 SYMBOL Misc\\signal 0 144 R0 WINDOW 3 -135 160 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V3 SYMATTR Value PULSE(0 5 0 .9u .9u 10u 20u) SYMBOL res 160 16 R0 SYMATTR InstName R2 SYMATTR Value 10k SYMBOL npn 192 96 R0 SYMATTR InstName Q3 SYMATTR Value 2N3904 SYMBOL res 160 128 R0 SYMATTR InstName R4 SYMATTR Value 1k SYMBOL pnp 192 368 M180 SYMATTR InstName Q4 SYMATTR Value 2N2907 SYMBOL res 64 128 R0 SYMATTR InstName R3 SYMATTR Value 100 SYMBOL res 240 352 R0 SYMATTR InstName R5 SYMATTR Value 5k SYMBOL res 288 0 R0 SYMATTR InstName R6 SYMATTR Value 5k TEXT 24 -32 Left 2 !.tran .001

Jamie