Digital to analog converters (DAC) are used to convert digital signals to analog values. The digital system providing data to the analog converter may be highly tasked. A DAC is provided with some in built logic to assist in reducing the load on the devices driving the DAC. The DAC may include a library of functions that it can apply to the input words to modify transitions in the analog output words. The DAC may further include a health checking system for monitoring the digital words being supplied to the DAC and raising a concern, and taking action if required, if the sequence of words is unlikely to be correct or beyond the target operating range.