ds1803 works well--thanks all

hi ,
thank q guys for ur interest...i have used a difference
amplifier using opamp..where the gain can be varied from -4 to 4...and ds1803
works well...i have finished my complete design

design:-

give the input to negative and positive terminals of the opamp

for negative terminal...Rin=10 k and Rf=40k
Rof=13.4(Rf/gain) gain= Rf/Rin (40/10)

for positive terminal...uses a 10k potentiometer (with a end at input
signal andother at ground) and the wiper of potentimter is attached to
the opamp terminal....

so varing the poetentiometr wiper from input voltage to ground u can
get gains from 4 to -4

i have succesfully used ds1803 controlled by 8051 microcontroller to
implement this

-bye guys...thanks again
-sanjay