公开(公告)号：US20250067595A1

公开(公告)日：2025-02-27

申请号：US18613515

申请日：2024-03-22

Applicant: Apple Inc.

Inventor： Anand K. Chamakura ,  Stephen N. Sweet ,  Ali Motamed ,  Dong Zheng ,  Jianjun Guo ,  Chau H. Nguyen

IPC: G01J1/46 ,  G01J1/42 ,  G01J1/44

Abstract: An electronic device may have a sensor to measure ambient flicker. The sensor may be a sigma-delta converter. The flicker may be calculated based on the voltage output of the sigma-delta converter and the number of times the sigma-delta converter is triggered during a predetermined period, thereby reducing the voltage output. In particular, a fast Fourier transform (FFT) may be used on these values to determine the flicker. If desired, filtering and/or non-uniform sampling may be incorporated to avoid aliasing. Additionally or alternatively, a Lomb-Scargle spectral analysis may be used to prevent the attenuation of the measured flicker signals. As an alternative to using a sigma-delta converter to determine ambient flicker, a folding capacitive transimpedance amplifier (C-TIA) circuit or a circuit with an analog to digital converter and digital filter may be used to measure the ambient flicker.