A 640×480 active chip for cell detection with 11b digital output

A microelectronic chip for the ultra-rapid detection of cells in few micro-liters drop samples is presented. The architecture is based on a two-dimentional 640times480 array of microsites. Dielectrophoresis (DEP) is the physical phenomenon used to manipulate the cells. A corresponding array of photodiodes is used for integrated optical detection. The chip implements a column-parallel, reconfigurable read-out and A/D conversion. The single readout channel is composed by a pre-amplifier with programmable gain and an algorithmic analog-to-digital converter with a 1.5-bit/stage architecture. The chip is implemented in 0.35 mum CMOS technology with a 3.3 V supply.