An amplifier having an inverting input and a non-inverting input; a capacitor coupled to inverting input of the amplifier; an input voltage conveyance control circuit, having a first switch and a second switch, the first switch coupled to the capacitor, and the second switch coupled to the non-inverting input of the amplifier; a reference voltage conveyance control circuit having a third switch and a fourth switch, a shared node coupled between third switch and fourth switch, the fourth switch coupled to the non-inverting input of the amplifier; a fifth switch coupled to an output of the amplifier; a leakage control circuit having a sixth switch and seventh switch, the sixth switch coupled between the inverting amplifier input and the fifth switch, the seventh switch coupled to the sixth switch and the capacitor; and a first resistor coupled from the output of the amplifier to the first switch.