DC voltage attenuation

I need to attenuate 0-5V to 0-1 mV.

The output of simple voltage dividers (normal op amps or resistor divider) can't be distinguished from baseline noise (baseline noise is 10-20mV.)

How can I attenuate the input voltage (0-5V) to get a 0-1mV low noise output?

• The baseline noise depends on the impedance of the circuit. Noise across a 1 Ω output resistor would be far less than across a 1 MΩ resistor. Noise across a wide bandwidth will be greater than across a circuit of lower bandwidth. Jun 7 at 21:57
• If using an oscilloscope to view the output from the divider try one thing; connect the oscilloscope probe tip to 0 volts and see what noise your o-scope inherently picks up. Jun 7 at 21:57

For example, 49.9K$$\\Omega\$$/10$$\\Omega\$$ divider will have J-N noise of less than 0.5nV/$$\\sqrt{\text {Hz}}\$$ at room temperature. 1mV of signal is huge compared to that.