Current controlled fet?

Dec 22, 2009 4 Replies

We have IGBT's but what about the reverse? A mosfet like device who's gate is current controlled? This might not seem very useful but they would remove the need for special drivers?



BJT. Verrrry special technology.

www.wescottdesign.com

Not really much of a stretch... integrated lateral PNP's include a plate (gate) over the base region, so they are MOS-like but with base current. ...Jim Thompson

| James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Help save the environment! Please dispose of socialism properly!

Or if you want another 4-layer structure, they make SCRs, and complementary to IGBTs, they also make IG SCRs (I forget the proper acronym).

Structurally, a BJT is indeed analogous. That reminds me, I need to find a four-lead MOSFET and see if I can use its substrate as base of an NPN. I'm guessing beta is poor, but might be equal in both directions.

Tim

-- Deep Friar: a very philosophical monk. Website:

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Tim - looking for an isolation transistor for a "wired-or" bus? If so, look at some of the 2 transistor 6 pin devices from Rohm & ? & ? - don't rember the names. Both way gain isn't shown in the specs & you'll need to get them and measure for that spec. The ones I've seen were quite effective on a 5v bus.

Hul

Tim Williams wrote:

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