A high performance peak-detect and hold circuit for pulse height analysis

A novel architecture is presented with performance exceeding previous state-of-the-art designs. A droop rate ranging from 125 mu V/ mu s to 1 mu V/ mu s and a charge injection of 5 mV are reported along with a 2.2-MHz bandwidth, a 38-V/ mu s slew rate, and integral nonlinearity 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 analog-to-digital converter (ADC) system using the new peak-detect and hold circuit architecture. The complete system has a differential linearity of 1.5% at 64 K conversion gain, an integral linearity of +or-0.016%, and an effective conversion time of 1.9 mu s for a count rate of 210000 c/s to the input of a pulse processor producing 3- mu s-wide pulses.<>