Design of Nupix-A1, a Monolithic Active Pixel Sensor for heavy-ion physics

A Monolithic Active Pixel Sensor (MAPS) named Nupix-A1 has been designed in a 130 nm process for the heavy-ion experiments at HIRFL and HIAF. The Nupix-A1 can simultaneously measure particle hits’ energy, arrival time, and position. The Nupix-A1 consists of 128 × 64 pixels with the size of 30μm × 30μm. A configurable DAC array, which consists of four 10-bit voltage DACs and seven 8-bit current DACs, tunes the bias of the in-pixel circuit. The analog signal from the pixels in four adjacent columns is converted into a digital signal by an 11-bit column-parallel ADC. The digitized data is encoded, serialized, and transmitted by the 5 Gbps data transmission link. This paper will discuss the design of the Nupix-A1.