Wow, that triggered a lot of replies, thanks!!! Now I think I would like to change the subject of the posting to "Voltage divider"; what I want to do is generate voltages (from a voltage reference) by whatever tecnology is practical. I ruled out resistor divider as to complex and then PWM seemed an obvious path as I worked quite a lot with switch mode amplifiers. But I will also take a second look at DACs. I remember there is an LT? paper on a 20 bit reference DAC solution. This is brainstorming time! So, I got a lot of reading and thinking to do...

Jan Fredriksson <jan@41hz.com> writes: > Wow, that triggered a lot of replies, thanks!!! > > Now I think I would like to change the subject of the posting to "Voltage > divider"; what I want to do is generate voltages (from a voltage reference) > by whatever tecnology is practical. I ruled out resistor divider as to > complex and then PWM seemed an obvious path as I worked quite a lot with > switch mode amplifiers. But I will also take a second look at DACs. I > remember there is an LT? paper on a 20 bit reference DAC solution. This is > brainstorming time! <http://www.linear.com/docs/4177> That uses a 24 bit ~1ppm ADC to measure and correct the output of a less accurate DAC. It is a nice idea, but it is also possible - now - to simply go out and buy a 20 bit DAC. <http://www.analog.com/en/digital-to-analog-converters/da-converters/ad5791/products/product.html> > So, I got a lot of reading and thinking to do... Have fun! -- John Devereux