Back to DAC noise.... I have been looking into using an external SPI DAC to get good noise performance and wonder if the mbed performance could be improved by those with the knowledge. Firstly for my application I'm using the dac as a voltage reference where the resolution is adequate, but the output noise isn't. So looking at dac designs and performance the noise seems to be due to clock feed through. On SPI parts I can stop sending SPI commands and hence remove the clock and signal spike feedthrough, but can this be done internally with the mbed? See my previous post which shows the noise [[http://mbed.org/forum/electronics/topic/3375/?page=1#comment-17157]] I now pressume the 400kHz noise is actually the internal dac clock/bus which is what I would like to disable once my analogue output voltage is set.