Integrating analog-to-digital converter

摘要

An integrating analog-to-digital converter for producing a digital output signal representing the value of an analog input signal which may have either a positive or negative polarity. The converter uses a switching circuit to reverse an integrator capacitor between charge and discharge periods so that the same input-signal-controlled current source can be used to both charge and discharge the capacitor. This results in inherent zero calibration because any offset errors during the charge cycle are cancelled out by equal and opposite offsets during the discharge cycle.