Hi, I want to supply a circuit fro

[KWOL]

Hi,
I want to supply a circuit from USB port. The circuit is a precision measurement device (includes 4 AD7730s), so I need a very low noise 5V (+-0.2V) power supply (max I=300mA). Since the USB port can supply (noisy and unstable) voltage in range 4.5-5.5V, I'm considering using a step-up or SEPIC converter to increase voltage to 5.5-6.0V (e.g. MAX1896) and then clean it with a low-noise LDO to 5.0V. How do you find this idea? Have somebody done something like this? With what effects? Maybe you would suggest any other solution?

Regards,

KWOL

 

[nbucska]

Usually only a part of a circuit requires precise/quiet VTG.
Concentrate the filtering there <nbucska@pcperipherals.com>

 

[jbartos]

Suggestion: Visit

http://www.maxim-ic.com/cookbook/powersupply/

for some low noise power supplies