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.

LATRIC0 is a single-channel readout chip designed for the Outer Tracker (OTK) of the reference detector on the Circular Electron Positron Collider (CEPC). The OTK employs AC-coupled Low-Gain Avalanche Detector (AC-LGAD) microstrip sensors to achieve high-precision spatial (10 µm) and timing (50 ps) measurements. Fabricated using a 55 nm CMOS process, LATRIC0 integrates an analog front-end amplifier and an event-driven ring-oscillator-based Time-to-Digital Converter (TDC) in a compact architecture. Measurements show that the prototype achieves a Least Significant Bit (LSB) of approximately 30 ps from both Time-over-Threshold (TOT) and Time-of-Arrival (TOA). The TDC core consumes less than 1.0 mW, while the total power of the front-end and TDC together is below 7.0 mW. The measured Integral Nonlinearity (INL) and Differential Nonlinearity (DNL) are within 1 LSB. LATRIC0 not only validates the proposed timing architecture but also establishes a foundation for the development of a future fully functional version with 128 channels and 100-µm channel pitch.