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

Claim 14:
15. An analog-to-digital conversion (ADC) method, comprising:
receiving an analog input signal at a first quantization stage;
sampling the analog input signal at the first quantization stage to generate a first digital signal;
generating a quantization error signal at the first quantization stage based on a comparison of the analog input signal and the first noise-shaped digital output;
filtering the first digital signal with a first noise-shaping transfer function to generate a first noise-shaped digital output;
receiving the quantization error signal at a voltage controlled oscillator (VCO)-based second quantization stage, and sampling the quantization error signal to generate a second digital signal;
filtering the second digital signal with a second noise-shaping transfer function to generate a second noise-shaped digital output;
filtering 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;
filtering 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
combining the first stage digital output and the second stage digital output to generate a digital ADC output signal with second order noise shaping characteristics.