A 6-bit 122 MS/s digital-to-analog converter for contactless applications in CMOS 90 nm technology

This paper describes a 6-bit 122 MS/s CMOS current steering digital-to-analog converter (DAC) for contactless applications. Main design requirement for proposed circuit was the ability to generate ISO 14443 and ISO 15693 compliant signal for 13.56 MHz contactless communication while maintaining minimum area and power consumption. Presented DAC architecture consists of globally biased matrix of unary current sources. Each source is accompanied by a latch holding present state of the cell and AOI gate, which controls on/off state based on input signals from external binary to thermometer code decoder. The design was implemented in UMC CMOS 90 nm technology process and resulted in complete layout of circuit along with sets of post-layout and mismatch simulations.