On 05/07/06, Wouter van Ooijen <wouter@voti.nl> wrote:
> > The input signal is 20v peak-to-peak (-10v to +10v)  ac 14Mhz
> > rf signal.
> > and i want to shift it to ( -15v to +5v ).  I looking for a
> > way to do it
> > without using additional power supply.
>

a) Series zener diode with pull-down resistor to -20V or so? (Not
particularly accurate).
b) Series Capacitor to remove existing DC and the a -5V voltage
soutrce feeding through a resistor to give you an offset? (Average
voltage will always be -5V)
c) fast opamp configured as an adder with a suitable input offset
voltage added. (Costly ?).

It depends what you really need.

Richard P
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