[time-nuts] Re: dual supplies Re: Re: DIY Low offset Phase Noise Analyzer (Erik Kaashoek)

2022-07-10 Thread Bob kb8tq via time-nuts
Hi I seem to recall TI having similar parts. The big gotcha is tossing large chunks of C onto the ground to rail connections. A typical op amp is not at all happy with this. Bob > On Jul 10, 2022, at 5:48 PM, Richard (Rick) Karlquist via time-nuts > wrote: > > > > On 7/10/2022 10:14 AM,

[time-nuts] Re: dual supplies Re: Re: DIY Low offset Phase Noise Analyzer (Erik Kaashoek)

2022-07-10 Thread Richard (Rick) Karlquist via time-nuts
On 7/10/2022 10:14 AM, Lux, Jim via time-nuts wrote: Yeah, but that virtual ground brings with it it's own set of problems. For instance, it has to both sink and source current, so you can't just use a 3 terminal regulator to create the midpoint, although I've seen schemes with a resistor

[time-nuts] Re: dual supplies Re: Re: DIY Low offset Phase Noise Analyzer (Erik Kaashoek)

2022-07-10 Thread glenlist via time-nuts
I've ALWAYS used an op-amp to nail down the half rail supply, I never use the two resistors and cap idea directly  unless the whole thing is quite basic Just don't put bulk capacitance on the output ! like I have seen in some bad designs. ROFL. Some op-amps are better at this than