A 14-Bit Digital to Analog Converter for a Topmetal-CEE Pixel Readout Chip

Abstract

The Lanzhou Heavy Ion Research Facility (LIRF) is the largest heavy ion research facility in China, providing a substantial volume of experimental data for fundamental research in nuclear physics. The Topmetal-CEE is a pixel readout chip specifically designed for tracking detectors. Within the Topmetal-CEE framework, the front-end amplifier and comparator necessitate precisely adjustable bias voltages. Hence, in this paper, a 14-bit resolution DAC with an R-2R resistor network structure is designed, along with an amplifier featuring high driving capabilities as the DAC driver, thus preventing potential impedance issues when driving large pixel arrays. Test results demonstrate that the DAC module, operating under a 3.3 V supply voltage, can consistently output voltages ranging from 0 to 1.8 V. Furthermore, the differential non-linearity error is less than 1.07 LSB, and the integral non-linearity error is less than 1.57 LSB.