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addaonyesterday at 10:03 PM2 repliesview on HN

A relevant part that changed my view of charge pumps is the LTC7820 [0]. This is an inductorless charge pump that can be used as a an unregulated voltage doubler or halver... at 500+ W and 98%+ efficiency. I used to think of charge pumps as designed for generating bias voltages where the actual power is quite small... but this shows that they scale quite well. (There's also the LTC7821 that combines the unreglated inductorless halver of the '7820 with a regulated, nominally-2:1 buck to give a regulated 48V -> 12V converter with some impressive efficiency numbers.)

[0] https://www.analog.com/media/en/technical-documentation/data...


Replies

em3rgent0rdrtoday at 5:18 AM

The '7660 is good for low-power and is my go-to DIP-8 part when I need a half or double voltage supply on a breadboard.

bsderyesterday at 11:03 PM

But, why use those parts?

These circuits take a lot of parts to do a job that you can do with modern high frequency stuff with a lot lower cost and parts count.

The normal point of a capacitive doubler is either to give you a voltage you need without a lot of extra parts count (often negative) or to generate a very high voltage.

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