[sdiy] Operational Transconductance Amplifiers

[Walker Shurlds]

On Tue, 9 Mar 2010 19:57:53 +0100
Andre Majorel <aym-htnys at teaser.fr> wrote:

> On 2010-03-09 12:42 -0600, Walker Shurlds wrote:
> 
> > does anyone know of a good website/book that explains [OTA]
> > thoroughly?
> 
> "An OTA is basically a two quadrant multiplier. It multiplies an
> input voltage by a control current and produces a current as its
> output. The OTA's transfer function is that of a differential
> transistor pair, which is pretty convenient, although, a bit tough
> to analyze."
> 
>   http://noniandjim.com/Jim/SecretsOfOTAs.pdf
> 

Thanks, that's helpful.  I also just discovered that NI's datasheet is
more thorough than I expect.  gm is determined by Iabc and
manufacturing constants, it seems.