Single-loop linear-exponential multi-bit incremental analog-to-digital converter

摘要

An incremental analog-to-digital converter (IADC) with a two-phase linear-exponential accumulation loop for improving the signal to noise distortion ratio (SNDR) and the dynamic range (DR) is disclosed. The linear-exponential IADC includes an analog modulator and a decimation filter. The analog modulator has an input for receiving the analog input voltage and an output. The analog modulator includes an integrator, an adder, a quantizer, a noise-coupling path, a data weighted averaging (DWA) circuit, and a digital-to-analog converter (DAC). The decimation filter has an input for receiving signals from the output of the analog modulator. The decimation filter includes a 1^st order accumulator, an exponential accumulator, and a decimator. The linear-exponential IADC is configured to operate with a linear phase for suppressing the thermal noise and an exponential phase for boosting the SQNR.