[sdiy] 4 bit D2A converter

[Tom Wiltshire]

On 2 Oct 2011, at 05:29, dan snazelle wrote:

> I am putting something together which requires a 4-bit D2A.
> 
> is there a way to use an 8 bit D2A chip somehow and maybe just ground the lowest least significant bits?
> 
> or would an R2R be the way to go for so few bits?

I'd definitely look at either R2R or weighted resistor values for so few bits. A whole DAC chip seems like overkill.

One possibility would be to use an op-amp inverting mixer, with four weighted inputs (5K, 10K, 20K, 40K?). I know logic voltages vary a bit, but it'd be close enough for four bits.

HTH,
Tom