Open AccessA Hybrid Audio ΔΣ Modulator with dB‐Linear Gain Control Function
Author(s) -
Kim YiGyeong,
Cho MinHyung,
Kim Bong Chan,
Kwon JongKee
Publication year - 2011
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.11.0111.0293
Subject(s) - jitter , integrator , chopper , electronic engineering , automatic gain control , dynamic range , cmos , electrical engineering , engineering , voltage , amplifier
A hybrid ΔΣ modulator for audio applications is presented in this paper. The pulse generator for digital‐to‐analog converter alleviates the requirement of the external clock jitter and calibrates the coefficient variation due to a process shift and temperature changes. The input resistor network in the first integrator offers a gain control function in a dB‐linear fashion. Also, careful chopper stabilization implementation using return‐to‐zero scheme in the first continuous‐time integrator minimizes both the influence of flicker noise and inflow noise due to chopping. The chip is implemented in a 0.13 μm CMOS technology (I/O devices) and occupies an active area of 0.37 mm 2 . The ΔΣ modulator achieves a dynamic range (A‐weighted) of 97.8 dB and a peak signal‐to‐noise‐plus‐distortion ratio of 90.0 dB over an audio bandwidth of 20 kHz with a 4.4 mW power consumption from 3.3 V. Also, the gain of the modulator is controlled from –9.5 dB to 8.5 dB, and the performance of the modulator is maintained up to 5 ns RMS external clock jitter.