Imaging system with a digital conversion circuit for generating a digital correlated signal sample and related imaging method

• Main Authors: Ganguly, Arundhuti, Roos, Gerhard P, Mollov, Ivan
• Format: Patent
• Language: English
• Published: 13.07.2021
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

An example imaging system includes a digital conversion circuit and a plurality of pixel circuits each having a photodiode, a biasing circuit, a charge-to-voltage converter, and a switch. The photodiode is configured to generate charges in response to light or radiation. The biasing circuit includes an operational amplifier having an input signal port for receiving a bias reference signal which controls a bias current flowing through an internal circuit of the operational amplifier. The charge-to-voltage converter is configured to accumulate the charges drained by the biasing circuit and convert the accumulated charges into a corresponding output voltage. The switch configured to selectively couple the charge-to-voltage converter to at least one data line. The digital conversion circuit is configured to generate a digital correlated signal sample for each pixel circuit using a difference between a digital signal sample and a digital reset level sample.