This is the circuit I have to create a negative rail for a local op-amp which needs the rail in order to manage to get low on the output rail. I've tried running a single supply but that did not perform well enough. The circuit works and with my diodes I get an output of -4.4V from 5V positive which is enough for my needs.
The problem is that the output is a bit noisy and I can see some low freq. pickup as well. How can I filter the output of the circuit? I've tried to increase the C4 capacitor which reduced the noise however the did not change the low freq. pickup.
The circuit will supply an op-amp used in analog circuit so low noise is important.
UPDATE: The schematic was wrong (did it in a hurry before leaving duh), however the circuit was hooked up correctly.