A current source is provided for use with integrated circuits such as programmable logic device integrated circuits. The current source has an operational amplifier with positive and negative inputs and an output. The output is connected to a common-source output stage. A current mirror circuit is connected between the common-source output stage and a positive power supply. An external circuit-board-mounted resistor and capacitor are connected in parallel between the common-source output stage and ground. The negative input of the operational amplifier receives a bandgap reference voltage. A feedback path is used to feed back a feedback signal from the output stage to the positive input of the operational amplifier. The feedback arrangement ensures that the bandgap reference voltage is applied across the external resistor, which, through operation of the common-source output stage and the current mirror circuit, establishes the magnitude of the current source output.