Honkin' big pass transistors.

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Configuring a bunch power semis to handle it is the easy part- the real challenge is keep die temperature excursions, and thus die expansion, under control to avoid early failures due to that effect. This is a completely separate failure mechanism from heat related stress. You should be discussing heat sink capacity and thermal time constant designs that are larg compared to your duty, if that's possible.

As Jim said, it depends on the quantification of the two instances of the word "several" :-)

In the end it's all in the SOA, meaning the milliseconds, duty cycle, amps and volts. Figure 9:

That'll tell you how many you need and how well the load needs to be balanced between them. You can also stack them in series but that can get iffy.

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Regards, Joerg

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Still got eyebrows?

The minimum delay in the feedback loop is cycle_time/number_of_legs, plus some margin for stability.

Vladimir Vassilevsky DSP and Mixed Signal Design Consultant

Well, copper wire, switches, fuses, relays and connectors are all linear pass devices. I get the impression you really want a solid state switch or device with gain, though? Hundreds of amps usually means thyristors, thyratrons, IGBTs. If you really need a linear range of gain, though, as opposed to a switch, this is devices-in-parallel territory.

I tend to concur. For linear, I'd use mongo MOSFETs on a MONGO heatsink, maybe even liquid-cooled or something.

Cheers! Rich

1mS settling time isn't much of a challenge for a switcher, but the extreme pulsed duty means using parts sized for the peak. Only the heatsink size is reducible to the average loss.

It amazes me where you get these pulsed poer applications that are so regulation-critical. I bet if you looked closer, you'd find it was just an ignorant gandy-dance.

I'd be tempted to segregate those circuits that are actually supply voltage sensitive, and those that actually need power.

Where local regulation is critical, you might try a compound circuit - one to provide the juice and another to do the actual fine regulation and filtering, at the load.

RL