More Nonlinear

[tomg]

On 23-Jul-98, tomg wrote:
>On 23-Jul-98, Sean Costello wrote:

>>A question:  Can an LM3900 be used as a differential amplifier, running
>>off of a single-ended power supply?  

>Nationals app notes has a diff-Tachometer and diff-integrator. Looks like a
>diff-amp would be easy, but no examples.

>-Tom

Wrong book!

National App Notes Vol 1, AN72-1O Fig 25: Shows a gnd ref diff amp.

V1 - inv-input  - 1OM Ri / 1OM Rf / 1.5M +V
V2 - non-input  - 1OM Ri / 1OM gnd / 1.5M +V
output          - diode anode / cathode to 1OM Rf / Rl = 1OK
 
Common mode biasing to allow V1 & V2 to vary over a +1V to -13V
range(looks odd to me too..) when operated from a +15V supply.

-Tom