> 1. Use an analog multiplier like the AD633 and wire it so
> that it multiplies X times Y. Feed your sine wave at 1 Volt p-p
> into the X input
> and your DC voltage into the Y input and the output will do what you
> wish.
>
> 2. Use a DAC like the MAX530 and wire it for Four Quadrant
> Mutiplication.
> (look in the data sheet for the circuit )
> Feed your appropriately scaled Sine wave into the the DAC's Vrefin
> and the
> amplitude will be controlled by the dacs digital code setting.
>
> Roger
>
> ----------
> > From: GERRY COX <
EraseMEgcoxspam_OUTTakeThisOuTDEK.COM>
> > To:
PICLISTspam_OUTMITVMA.MIT.EDU
> > Subject: DC level to 1KHz sine wave conversion.
> > Date: Thursday, February 12, 1998 12:20 PM
> >
> > My latest project involves a PIC16C73A , which amongst other things,
> drives
> > a serial 16bit DAC. This gives me a control voltage programmable
> from 0
> to
> > 10V.
> > I also need to generate a sinewave of nominally 1KHz. The p-p
> amplitude
> > must track the DAC voltage and be always 10 percent of its DC
> voltage.
> > It has to be a reasonably clean and stable sinewave.
> > Input voltage range varies from 0.5 to 10V.
> > Sine wave output will vary 0 to 1V p-p for the above input range.
> Accuracy
> > better than 3%.
> > Sine wave Total Harmonic Distortion better than 5%
> > Sine wave frequency accuracy 1Khz +/- 100Hz
> > Output current 5mA max.
> > Power supply - I have +15V, -15V and +5V available.
> >
> > For example if I have a DC input of 3V the sinewave generator should
> output
> > 300mV peak to peak at 1Khz.
> > this 300mV should be accurate to 309mV max or 291 mV minimum.
> >
> > I am considering an MF10 switched capacitor filter with clock 128
> times
> that
> > of the 1KHZ output but am looking for ideas
> >
> > All ideas welcome. Must be reasonably low component count but parts
> cost
> is
> > not paramount for a change!
> >
> > Regards,
> > Gerry Cox