[sdiy] quick 13700 question

[Antti Huovilainen]

On Fri, 26 Jun 2009, René Schmitz wrote:

> Dan Snazelle schrieb:
>>
>> can someone refresh my memory on how to figure out the gain for an OTA 
> stage (13700)
>
> G = gm*RLoad, where gm = 19.2*Iabc IIRC.

And 19.2 just happens to be 1/2Vt.
The full function for OTA is Iout = Iabc*tanh(Vin / 2Vt)
You can calculate how hot signal you want from that.
In typical OTA filters you can use hotter signal than in VCA because of 
the negative feedback that operates below cutoff.

Antti

"No boom today. Boom tomorrow. There's always a boom tomorrow"
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