A HIGH-PERFORMANCE PEAK-DETECT AND HOLD CIRCUIT FOR PULSE-HEIGHT ANALYSIS

Peak extractor circuits are an important link in most pulse-height analysis systems. Their performance will affect peak broadening, throughput, integral and differential linearity. A novel architecture is presented with performance exceeding previous state-of-the-art designs. A droop rate ranging from 125 muV/mus to 1 muV/mus and a charge injection of 5 mV are reported along with a 2.2 MHz bandwidth, a 38 V/mus slew rate and integral non-linearity of 50 ppm. The low droop rate allows temporary storage of the signal in an analog FIFO with minimal peak broadening, suitable for high resolution low energy x-ray analysis. This configuration has been implemented in an ADC system using the new Peak-Detect & Hold circuit architecture. The complete system has a differential linearity of 1.5% at 64K conversion gain, an integral linearity of +/- 0.016%, and an effective conversion time of 1.9 mus for a count rate of 210,000 c/s to the input of a pulse processor producing 3 mus-wide pulses.