Abstract: A high-precision Delta-Sigma modulator tailored for audio codecs is introduced in this paper. It adopts a CIFF architecture characterized by a high input dynamic range. The loop filter is configured as a third-order single-loop structure, integrated with a 4-bit quantizer to mitigate the overload probability of switched-capacitor integrators in high-order systems and simultaneously elevate the Signal-to-Noise and Distortion Ratio (SNDR). A Programmable Gain Amplifier (PGA) serves as the input stage of the Delta-Sigma modulator, amplifying input signals in scenarios of low-amplitude inputs to broaden the modulator's dynamic range. Additionally, Data Weighted Averaging (DWA) technology is implemented to effectively suppress harmonics arising from nonlinear mismatches in feedback capacitors during manufacturing. Fabricated based on the SMIC 180 nm process, the modulator achieves an SNDR of 102.7 dB and a Dynamic Range (DR) of 106 dB in post-simulation under conditions of a 1.8 V power supply voltage, a 3.072 MHz sampling clock frequency, a 64-times oversampling rate, and a 24 kHz signal bandwidth. The modulator consumes 1.6 mW of power and exhibits a FoM_SNDR of 174.5 dB and a FoM_DR of 177.8 dB. When dealing with low-amplitude inputs and with the PGA enable, an extra 1.69 mW of power is consumed, potentially boosting the SNDR by up to 5.93 dB.