Ad converting circuit, photoelectric converting apparatus, image pickup system, and driving method for ad converting circuit

摘要

An apparatus for acquiring an i-bit digital code by a first stage AD conversion and a j-bit digital code by a second stage AD conversion includes a comparing unit which compares a reference signal and an analog signal in the first stage AD conversion; and an amplifying unit for outputting an amplified residual signal acquired by amplifying a difference between the analog signal and an analog signal corresponding to the i-bit digital code. The comparing unit compares the amplified residual signal and the reference signal in the second stage AD conversion.

主权项

1. An apparatus for acquiring an i-bit digital code by a first stage AD conversion and a j-bit digital code by a second stage AD conversion comprising:
a comparing unit which compares a reference signal and an analog signal in the first stage AD conversion; and an amplifying unit which outputs an amplified residual signal acquired by amplifying a difference between the analog signal and an analog signal corresponding to the i-bit digital code, wherein: i and j each is an integer equal to or greater than 2, the comparing unit compares the amplified residual signal and the reference signal in the second stage AD conversion, the amplifying unit comprises a differential amplifier, and the comparing unit and the amplifying unit share the differential amplifier.