Leakage Current Compensation for the 0.13 μm CMOS Charge Sensitive Preamplifier

The active hybrid pixel detector (APD) can be a valuable solution in front-end electronics for radiation sensors. Detection systems with high sensor pixilation can benefit from low power, low parasitic, high front-end channel density, and low cost per channel. In addition, the APDs are characterized by good radiation tolerance [1-3] and can integrate large amount of additional signal processing and functions in analog, mixed-signal and digital domains, offering further advantage in terms of power. Submicron CMOS technologies ensure radiation hardness required by detector readout systems in present high-energy physics experiments as well as in other application fields [2-5]. CMOS is the most widely used technology for readout and control of imagers. CMOS low-noise preamplifiers for the active hybrid pixel detector were presented in [6]. APD are based on Si, GaAs, CdTe sensors connected to dedicated front-end electronics chips using the bump and flip-chip technology. A typical electronics read-out system consists of a charge sensitive preamplifier (CSP), realized with an amplifier with a capacitive feedback, a shaping filter, and an ADC. The incoming particles generate charge in the detector which is being integrated by the preamplifier and filtered with the shaper, in order to obtain the proper time evolution. Then, ADCs convert the signal amplitude for the successive storing in a computer. A general description of the electronic readout system which is based on a CSP was previously reported in [6-7]. In this paper the authors attempt to derive some design aspects for the CMOS preamplifier of hybrid pixel detectors used in particle tracking, operating in the nanoampere region. The experimental simulation results obtained with CSP for APD imaging implemented in CMOS 0.13 μm are reported. In that work, we are simulated a scheme for producing a high-value feedback device and leakage current compensation circuits. Analysis of Mathematical Formulae of Equivalent Noise Charge