| 摘要 |
A system for detecting high speed noise in active pixel sensor (APS) devices, such as CMOS devices, comprises photodiode 110, reset transistor 120, amplifier transistor 130, row select transistor 140, and high-speed analog-to-digital convener (ADC) 150. Reset transistor 120 gate receives a reset signal, and the drain receives a reset voltage. The gate of amplifier 130 is connected to photodiode 110 and reset transistor's source, and receives a drain supply voltage. The gate of row select transistor 140 receives a row select signal, the drain terminal being connected to the amplifier transistor source. High-speed ADC 150 is connected to row select transistor 140 source and capable of resolving high-speed excitation events received by the photodiode. Such high speed noise may result from random alpha particle or gamma ray photon excitations, depositing large energy amounts in single array pixels. A predictor 510 and DAC 520 may compensate for noise events; alternatively, a driver (170, Figure 4) may be used. Also, independently claimed is a method comprising converting an amplified voltage from a photodiode, in the presence of a high speed noise event, using an ADC circuit capable of resolving event signals up to a first frequency threshold.
|
