CMOS Readout Circuit with New Background Suppression Technique for Room-Temperature Infrared FPA Applications

Abstract

A high-performance CMOS readout integrated circuit (ROIC) with a new temperature and power supply independent background current and dark current suppression technique for room-temperature infrared focal plane array applications is proposed. The structure is composed of an improved switched current integration stage, a new current-mode background suppression circuit, and a high linearity, high voltage swing output stage. An experimental readout chip has been designed and fabricated using the Chartered 0.35 µm CMOS process. Both the function and performance of the proposed readout circuit have been verified by experimental results. The test results show that the detector bias error in this structure is less than 0.1 mV. The input resistance is close to an ideal value of zero, and the injection efficiency is almost 100%. The output voltage linearity of the designed circuit is more than 99%. The background suppression level is tunable between 8 nA-1.5 µA, and the background suppression uniformity is as high as 100%. A unit-cell occupies a 10 µm × 15 µm area and consumes less than 0.07 mW power.

Low-Power Low-Noise CTIA Readout Integrated Circuit Design for Thermal Imaging Applications

“…From equation (15), the value of R Z will control the RHP zero and equal 1/g m6 to eliminate it. Now, the resistance R Z will be replaced by a transistor M9 so the aspect ratio (S 9 ) of transistor M9 can be determined by [21]:…”

“…Basically, the DR is limited by the maximum integration voltage (V max ), the integration capacitor (C int ) and the readout noise of the circuit as shown in equation (1) [15] where, q is the electron charge. The DR can be widened either by changing the C int values [4][5][6][7][8][9][10][11][12][13][14][15][16], or by changing the integration time [9,12]. (1) This paper concerns with the application of a new widening DR technique to the CTIA ROIC based on the CDS circuit with emphasis on its power consumption and noise performance compared to other works.…”