As the leading research platform of heavy-ion science in China, the heavy-ion physics and heavy-ion applications at the Heavy Ion Research Facility in Lanzhou (HIRFL) drives the development of new detector technology. Thus, a Monolith Active Pixel Sensor (MAPS) is has been designed in a 130nm CMOS process.
The pixels can record the energy, time, and position of the hit particles. To be tuned and characterized for different applications, the pixels have been designed in a configurable method. This is done by providing the current and voltage to the pixel with a configurable DAC array, which consists of four 10bit voltage DACs, seven 8bit current DACs, a Bandgap, and an I2C interface. The voltage DAC is implemented with an R-2R resistor ladder network and each LSB corresponds to 2.4mV. The current DAC is in current-Steering type with thermometer Code. Each LSB of the current DAC corresponds to 10nA. The Bandgap provides a stable, temperature-independent reference current of 10uA and voltage of 600mV to the DACs. All the DACs can be accessed and configured with the I2C interface. The DAC array covers 3074*400um2 and the power consumption is 46.2mW. This paper will discuss the design, integration and performance the DAC array with the pixels in the MAPS.