At 08:00 AM 3/2/2004 -0800, you wrote:
>I have a circuit, that uses a voltage divider on a control pin, to turn it
>on and off.  Basically if the voltage is present, and above a 1.32V
>threshold, then the controller is activated.  I want to remotly control this
>device, so I tied a N channel FET (BSS138) where the source is tied to the
>control pin, and the drain is tied to ground, and the gate has a 1K pulldown
>and then driven from a PIC.

I think you've got drain and source reversed. The MOSFET will actually
sort-of work in reverse, but the body diode is conducting and keeping
the source voltage from going more than one diode drop above ground.

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

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