I've got an analogue circuit with a gain of a few thousand. I note that the 78M05 and 79M05 regulators providing the +/-5V rails have a couple of mV ripple at a few kHz (the input signal being amplified, causing increased drain in IC's down the line) and I'm concerned it will couple into other, more sensitive parts of the circuit. I've tried LM317 / LM337 regs but they don't seem any better, despite a 10uF decoupler on their ref pins, perhaps because their ripple rejection is intended for mains frequencies rather than kHz. I've noticed that there are some expensive regulators touted as "fast transient response" around, do people find these significantly reduce supply ripple, i.e. coupling between IC's in analogue circuits?
- posted
13 years ago