[sdiy] Obvious choice for precise 1.00V reference?

[David G. Dixon]

> In case anyone is curious, it looks like the Analog Devices ADR510 might
> be
> a good choice. 1.0V output, +/-0.35% accuracy, needs only one bias
> resistor
> (which doesn't have to be of high accuracy) and an optional capacitor "for
> additional filtering of the supply".

The only issue is the temperature coefficient isn't as low as some other
common references (70 ppm/C max, compared with 25 ppm/C max for REF0X and 10
ppm/C max for REF10X).  However, the convenience of a 1V reference instead
of 5V or 10V probably outweighs this minor issue.  Also, the ADR510 can be
configured as a -1.0V reference very easily, which the others cannot.
Hence, with a low-offset opamp and a few hand-selected precision resistors,
a DPDT switch to select the polarity, and a rotary switch to select the
opamp gain, one could build a very nice precision voltage source for VCO
calibration.  (I think I'll do it.)