This paper presents a switched-capacitor high-pass delta-sigma modulator that can directly convert a chopper modulated signal to the digital domain. Low power consumption is achieved by employing inverter-based amplifiers and dynamic biasing in the first amplifier with relaxed slew-rate requirements as a result of the multi-bit quantization. The mismatch errors in the switched-capacitor DAC are first-order noise shaped by a tree-structured dynamic element matching encoder. Schematic level simulations show that the high-pass modulator achieves a peak SNDR of 96.4 dB and a SFDR of 101 dBc over a bandwidth of 300 Hz. The total estimated power consumption of the modulator is 19.56 µW leading to a figure-of-merit of 0.6 pJ/conv.
['Nikola Ivanisevic', 'Saul Rodriguez', 'Ana Rusu']
A 96.4 dB high-pass delta-sigma modulator with dynamic biasing and tree-structured DEM