High dynamic range CMOS pixel and method of operating same

摘要

A method of operating a CMOS pixel is disclosed. The CMOS pixel includes a photodiode (PPD), a transfer gate coupled to the PPD, and an anti-blooming drain coupled to the transfer gate. A potential barrier is formed between a potential well underlying the PPD and the transfer gate. Charge is accumulated in the potential well in response to electromagnetic radiation during a first integration time. Excess charge is removed from the potential well to the anti-blooming drain that exceeds the first potential barrier. A size of the potential barrier is increased. Charge is accumulated in the potential well during a second integration time.

主权项

1. A method of operating a CMOS pixel, wherein the CMOS pixel comprises a photodiode (PPD), a transfer gate coupled to the PPD, and an anti-blooming drain coupled to the transfer gate, the method comprising:
forming a potential barrier between a potential well and the transfer gate; accumulating charge in the potential well in response to electromagnetic radiation during a first integration time; removing excess charge from the potential well to the anti-blooming drain that exceeds the potential barrier; increasing a size of the potential barrier; and accumulating charge in the potential well during a second integration time.