A small area charge sensitive readout chain with a dual mode of operation

摘要

A charge sensitive readout chain has been designed and fabricated in a commercially available 0.8 μm CMOS technology. The readout chain is optimized for pixel detectors measuring soft X-ray energies up to 20 KeV. In the first mode an analog signal proportional to input charge is generated and processed in real time. In the second mode a peak-and-hold operation is enabled and the relevant signal is processed in later time. This dual mode of operation is controlled by an external digital signal. The readout chain consists of a charge amplifier, a shaper, an operational amplifier which can either operate as a voltage amplifier or a peak detector and an output buffer. Its area is 270 μm x 150 μm. The gain at the shaper output is 378 mv/fC, the ENC is 16 e{sup}- rms at 160 nsec shaping time. The overall gain is 557 mV/fC, the ENC is 13 e rms with 240 nsec peaking time and 1.4 μsec recovery time. The overall power dissipation is 1.5 mWatt with a load capacitance of 25 pF.