Enhanced auto-zero circuit

Multi-phase auto-zeroing amplifier circuitry comprising:

• an amplifier comprising an inverting amplifier input terminal, a non-inverting amplifier input terminal, and an amplifier output terminal;
• a first auto-zeroing network, comprising:
• an input capacitor, having a first input capacitor terminal and a second input capacitor terminal, the second input capacitor terminal coupled to the inverting amplifier input terminal;
• first and second switches, in a series arrangement between the inverting amplifier input terminal and the amplifier output terminal to define a first intermediate node between the first and second switches;
• a first auto-zero capacitor, connected between the inverting amplifier input terminal and the first intermediate node;
• a second auto-zero capacitor, connected between the first intermediate node and a first reference node;
• and
• an input auto-zero switch, coupled between the first input capacitor terminal and a second reference node, wherein the non-inverting amplifier input terminal is connected to the second reference node;
• and
• switch controller circuitry, configured to provide control signals for controlling the input auto-zero switch and the first and second switches, wherein during a first sub-phase of an auto-zero phase, the input auto-zero switch and the first and second switches are turned on to store an amplifier input offset coarser compensation charge on the input capacitor, and wherein during a second sub-phase of the auto-zero phase, the first switch is turned off before turning off the second switch to store an amplifier input offset finer compensation charge on the input capacitor via the first auto-zero capacitor.