AUTO-ZEROED AMPLIFIER WITH LOW INPUT LEAKAGE

摘要

An apparatus comprises an amplifier (340) having an inverting input and a non-inverting input; a capacitor coupled (350) to the inverting input of the amplifier; an input voltage conveyance control circuit (309), having a first switch (310) and a second switch (315), 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 (318) having a third switch (333) and a fourth switch (335), wherein a shared node (331) is coupled between the third switch and the fourth switch, the fourth switch coupled to the non-inverting input of the amplifier; a fifth switch (370) coupled to an output of the amplifier; a leakage control circuit (399) having a sixth switch (395) and a seventh switch (397), 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, a feedback resistor (360), coupled from the output of the amplifier to the first switch.