A 2.5 mW 80 dB DR 36 dB SNDR 22 MS/s Logarithmic Pipeline ADC

A switched-capacitor logarithmic pipeline analog-to-digital converter (ADC) that does not require squaring or any other complex analog function is presented. This approach is attractive where a high dynamic range (DR), but not a high peak SNDR, is required. A prototype signed, 8-bit 1.5 bit-per-stage logarithmic pipeline ADC is designed and fabricated in 0.18 mu m CMOS. The 22 MS/s ADC achieves a measured DR of 80 dB and a measured SNDR of 36 dB, occupies 0.56 mm(2) and consumes 2.54 mW from a 1.62 V supply. The measured dynamic range figure of merit is 174 dB.