millivolt voltage reference

Hey,

I'm working on a receiver circuit an I'm in need of a stable millivolt range reference for the final output stage.

The input signal is a modulated 40kHz carrier, much like any IR system. After reception, DC removal (47pF, 1MΩ) and amplification (INA128, x50,000), the threshold needed for a logical '1' is about 100mV.

I'm using a low-power comparator as a final output stage (TLC339).

I'd prefer to avoid further amplification, both from power and space considerations (and to avoid excessive negative bias on the comparator's inputs)

I was thinking on using a precision voltage reference (say, 4.096V), and feed that to a resistive voltage divider.

Question is, will it be stable enough, and whether there's a better way of achieving this low a reference?

Thanks in advance!

That is a reasonable way of doing it provided you want a fixed threshold, although I would probably use a 1.22V reference. Make sure you decouple the resistor divider connection to the comparator.

Keith

Hi z9u2k,
We have had "extreme" low voltage thresholds of 10...40mV, more as thousand exemplares, their are over 10 years in usage_with no problems of some instabilties... Our was 1.25V reference based too
Btw.; dont forget pls- you will need a very clean & properly bypassed threshold & supply voltage and clean, low impedance/high quality GNDs too...
K.