[sdiy] using a dac as a digitally controlled amplifier

[brianw]

On Aug 6, 2024, at 2:15 AM, Roman Sowa wrote:
> BTW, I don't know what technology is used in those modern multi GHz DACs used so widely today. Switching resistors at that speed sounds like technology stolen from aliens.

The fastest designs that I know of use current sources, and the switching is fast because the current is never turned off. It's merely redirected between the normal and inverted outputs. It's difficult to go beyond 14 bits, because there you have an MSB current source that is 16384 times the LSB current source ... very difficult to maintain precision across that range.

Which multi GHz DAC chip(s) are you looking at?

Brian