A printhead circuit or driving at least two actuating elements has a trim generating circuit for generating a trim signal using a comparator coupled to receive and compare feedback indicative of a present level of a drive voltage, with a configurable reference voltage value. The trim being based on a drive voltage feedback can give a more direct indication of actuating element output than given by timing references. Hence the trim can be more accurate, can be simpler, without accurate digital timing references, and thus costs can be reduced. It can be combined with a cold switch arrangement.