Patent ID: 10566991

Abstract:
A delta-sigma modulator architecture with idle tone suppression based on injecting an out-of-band signal includes: modulator input circuitry to provide a modulator input signal; modulator loop circuitry to quantize the modulator input signal to generate a modulator output signal at an oversampling frequency, and to provide a feedback signal. Digital filtering circuitry filters the modulator output signal to provide a digital output signal at a data rate frequency related to the oversampling frequency by a defined oversampling ratio. Out-of-band (OoB) signal generator circuitry injects a deterministic OoB injection signal at a defined OoB frequency outside of a target frequency band. The modulator input circuitry combines the analog input signal, the feedback signal, and the OoB injection signal into the modulator input signal. The digital filtering circuitry filters the OoB injection signal. The OoB injection signal can be selectively defined to suppress idle tones generated in the modulator loop circuitry.