Monolithic current integrator circuit as a building block of wide dynamic range ADC for calorimetry system

A monolithic charge-to-amplitude converter integrated circuit (QAC IC) was developed with a bipolar application-specific integrated circuit (ASIC) technology. The QAC IC could be used as a building block of a wide-dynamic-range analog-to-digital converter (ADC). Stacking more than two QAC ICs, one could achieve larger dynamic range than that of the single QAC. The QAC IC could be used in a narrow gate application as well as in a wide gate application. The QAC IC was examined in terms of input impedance, transfer function of the current signal, and linearity. The input impedance was kept 50 Omega up to 100 MHz. The integral nonlinearity was 0.1% for the maximum input charge of 600 pC. The dynamic range of the single QAC IC was 4000 pC. >