Analog Integrated Circuits and Signal Processing, 30, 137–147, 2002 Kluwer Academic Publishers.
ADAPTATION OF CURRENT SIGNALS WITH FLOATING-GATE CIRCUITS
PESAVENTO, A.,HORIUCHI, T., DIORIO, C., KOCH, C.
In this paper we present a new, adaptive spatial-derivative circuit for CMOS image sensors. The circuit removes its offset as a natural part of its operation using a combination of electron tunneling and hot-electron injection to add or remove charge on a floating-gate of an auto-zeroing amplifier. We designed, fabricated and successfully tested a chip with the circuit. Test results show that the circuit reduces the offsets by more than an order of magnitude.
Keywords: CMOS visual sensors, fixed-pattern noise removal, floating-gate circuits