A 10-Bit 300-MS/s Pipelined ADC With Digital Calibration and Digital Bias Generation

A 10-bit pipelined ADC was fabricated using a 65 nm CMOS technology. To reduce power consumption, switching opamps are used. These switching opamps are designed to have a short turn-on time. Digital background calibration is employed to correct the A/D conversion error caused by the low dc gain of the opamps. The biasing voltages in each opamp are automatically generated using digital circuits. This bias scheme can maintain the settling behavior of the opamp against process-voltage-temperature variations. At 300 MS/s sampling rate, the ADC consumes 26.6 mW from a 1 V supply. Its measured DNL and INL are + 0.52/-0.4 LSB and +0.99/-1.65 LSB respectively. Its measured SNDR and SFDR are 55.4 dB and 67.2 dB respectively. The chip active area is 0.36 mm² .