Hi all!
I am trying to build an application that uses the ADC12 and I need a low
noise power supply. I am using a TPS77733 regulator but it has a high
frequency noise of about 10mV uncharged (in the oscilloscope one can see
regular isolated pulses). When I charge it with an MSP430f149, noise
increases up to 20 mV peak to peak (but now you don't see isolated pulses
but a regular oscillation -reflecting the MSP operation for sure- ). This
variation is also reflected in Vref and results in fluctuations in
measurements of steady voltages. Can anybody please suggest me where to find
an example of a low noise power supply? I've been searching in the
application notes but I only found examples powered by batteries (what is
not an option in my case).
I can't understand either, why the noise in the output of the TPS increases
so much when charged by the MSP (it drains just a few uA). My test circuit
has all the capacitors suggested in the User guide.
Any help will be greatly welcome.
Best regards,
Claudio
PS: Sorry this is quite off topic but I'm really lost :-(
