Abstract
The work of the thesis is to develop a CMOS signal processing circuit to use with silicon photodiodes for low energy gamma and X-ray detection. The circuit consists of a preamplifier, an amplifier and a comparator for nuclear pulse signal shaping, amplification, and discrimination. The circuit is fabricated using a standard 0.5μm double-poly double-metal (DPDM) CMOS integrated-circuit process and takes a chip size less than 80μm x 50μm. The amplifier is based on a CMOS inverter and the comparator is a Schmitt trigger circuit, which have the merits of simple structure and low power consumption. The amplifier has a voltage gain up to 85 dB in the interested frequency range of 10 to 100 kHz. The circuit is operated under a single supply voltage of 3 volts and the total power consumption is less than 100μW. Sensitivity studies were also performed to evaluate the effect of manufacturing process uncertainties, operating temperature and power supply voltage fluctuations.