high voltage LDO

John Larkin · 2016-09-19T23:39:42+00:00

I need to regulate a +24 supply down to +22, 0.8 amps maybe. There's not much headroom for +24 drift, so I need an LDO. Few if any LDOs can tolerate +24 in. We stock LM2941, adjustable LDO, which for some reason is limited to an output range of +5 to +20. I suppose I could design my own reg, but that's silly. Anybody know of an affordable HV LDO chip? Microchip makes its MIC2941A without the LM2941 output restrictions. I could use that, with the LM as a backup source, I guess. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com

high voltage LDO

Sep 19, 2016 82 Replies

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Jim Thompson 9 years ago

Yep, use you recommended BCV62C SOT23 current mirror as the core plus any old transistors to make the cascode portion. ...Jim Thompson

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Winfield Hill 9 years ago

The only BCV62 matching spec is 0.7 / 1.3x current matching, corresponding to an about 10mV voltage offset matching spec. This is 5 to 10x worse than the parts in my Table 8.1b (such as the BCM857 and DMMT3906), and I think that's why I left those parts out of the table. They're also pre-wired as mirrors, limiting their application.

Thanks, - Win

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Phil Hobbs 9 years ago

If it runs away at 25 mW, it'll have about 10% nonlinearity at 2.5 mW. If t hat's good enough precision for the application, fine. I'm usually trying f or something quite a bit better than that.

Cheers

Phil Hobbs

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