Patent ID: 11870453
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An analog-to-digital conversion (ADC) circuit, comprising:
a first quantization stage configured to receive an analog input signal and sample the analog input signal to generate a first digital signal, the first quantization stage further configured to filter the first digital signal with a first noise-shaping transfer function to generate a first noise-shaped digital output and to generate a quantization error signal based on a comparison of the analog input signal and the first noise-shaped digital output;
a voltage controlled oscillator (VCO)-based second quantization stage configured to receive the quantization error signal and sample the quantization error signal to generate a second digital signal, the VOC-based second quantization stage further configured to filter the second digital signal with a second noise-shaping transfer function to generate a second noise-shaped digital output;
a first digital filter configured to filter the first noise-shaped digital output with an equivalent signal transfer function of the VCO-based second quantization stage to generate a first stage digital output;
a second digital filter configured to filter the second noise-shaped digital output with the first noise-shaping transfer function to generate a second stage digital output with second order noise-shaping characteristics; and
a combination circuit that combines the first stage digital output and the second stage digital output to generate a digital ADC output signal with second order noise shaping characteristics.