New design structure of a direct-injection input circuit with adaptive gain control techniques

Abstract

ABSTRACT Based on the application of the direct injection for per detector (DI) input technique, a new readout structure for theinfrared (IR) focal-plane-array (FPA), called the variable gain direct inject per detector (VGDI) is proposed and analyzed.The readout circuit of VGDI of a unit cell of photo-voltaic sensor under investigation, is composed of a direct inject perdetector circuit, high gain amplifier, and the reset switch. The VGDI readout chip has been designed in 0.5 pm double-poly-double-metal (DPDM) n-well CMOS technology in various formats from 8 X 8 to 128 X 128. The simulation 8 X 8VGDI of the readout chip have successfully verified both the readout function and performance. The high gain ,low power, high sensitivity readout performances are achieved in a 50 X 50 pm2pixel size. Keywords : photo-Voltaic, DI, VGDI, FPA, CMOS, DPDM, pixel size I. INTRODUCTION The photo-voltaic (PV) Infrared JR detector is potentially suitable for the low power in applications, and large arraysecond generation multispectral JR imagers because it has a much greater sensor resistance than the photoconductive JRdetector. Typically, the photo-voltaic signal readout circuit can be implemented using the voltage and current readout.Usually, the current readout is chosen because of the noise, bias point, and the power dissipation considerations. So, farseveral current readout schemes and structures such as the source follower per detector the capacitive transimpedanceamplifier (CTIA) the direct inject ( DJ ),