An Ultra Low Noise, Low Power Hybrid Preamplifier for X-Ray Spectrometry

A hybrid preamplifier for use with high resolution HgI2 x-ray detectors has been developed. Full scale discrete component circuits were tested, and the final design was hybridized as a standard 20-pin dip package. The preamplifier can be configured to operate as a resistor or pulsed feedback mode device. In the pulsed light feedback mode the electronic noise measured by the pulser method with the input transistor cooled to approximately -30°C was 19.6 electrons RMS. The equivalent input noise at room temperature was 22 electrons RMS, and the power consumption was 220 mW. In the resistor feedback mode corresponding values of 30 electrons RMS and 200 mW were measured.