公开(公告)号：US20240305246A1

公开(公告)日：2024-09-12

申请号：US18182101

申请日：2023-03-10

Applicant: Apple Inc.

Inventor： Eddie L. Ng ,  Adriane S. Niehaus ,  Ali Motamed

IPC: H03F1/02 ,  H03F3/217

CPC classification number: H03F1/0211 ,  H03F3/2171

Abstract: A switching-amplifier circuit for computer systems generates a buffered version of a received input signal. Power supply circuits coupled to the switching-amplifier circuit adjust driver power supply and driver ground supply voltage levels over respective continuous ranges of voltages based on a magnitude of the buffered signal. An output stage included in the switching-amplifier circuit generates an amplified version of the received input signal that includes a series of pulses that transition between the respective voltage ranges of the driver power supply and driver ground supply, where the respective widths or frequencies of the series of pulses encode a magnitude of the amplified version of the received input signal.

公开(公告)号：US10984732B2

公开(公告)日：2021-04-20

申请号：US16580150

申请日：2019-09-24

Applicant: Apple Inc.

Inventor： Dong Zheng ,  Ali Motamed ,  Anand K. Chamakura

IPC: G09G3/36 ,  G09G3/34 ,  H03F3/45

Abstract: An electronic device may have a display with an array of pixels configured to display images for a user. The electronic device may have an ambient light sensor for gathering ambient light information. The ambient light sensor may be at least partially covered by the display. The ambient light sensor may be switched into use during blanking periods when a portion of the display overlapping with the display is temporarily turned off. The ambient light sensor may include a photodetector, a first stage with an amplifier, first and second capacitors selectively coupled across the amplifier, and a second accumulation stage. During blanking time, the first capacitor may integrate photodetector current. During non-blanking, the charge stored in the first capacitor may be transferred to the second accumulation stage while the second capacitor applies an offset voltage to the photodetector to prevent undesired charge injection into the photodetector.

公开(公告)号：US20210090509A1

公开(公告)日：2021-03-25

申请号：US16580150

申请日：2019-09-24

Applicant: Apple Inc.

Inventor： Dong Zheng ,  Ali Motamed ,  Anand K. Chamakura

IPC: G09G3/34 ,  H03F3/45

Abstract: An electronic device may have a display with an array of pixels configured to display images for a user. The electronic device may have an ambient light sensor for gathering ambient light information. The ambient light sensor may be at least partially covered by the display. The ambient light sensor may be switched into use during blanking periods when a portion of the display overlapping with the display is temporarily turned off. The ambient light sensor may include a photodetector, a first stage with an amplifier, first and second capacitors selectively coupled across the amplifier, and a second accumulation stage. During blanking time, the first capacitor may integrate photodetector current. During non-blanking, the charge stored in the first capacitor may be transferred to the second accumulation stage while the second capacitor applies an offset voltage to the photodetector to prevent undesired charge injection into the photodetector.

公开(公告)号：US08717216B1

公开(公告)日：2014-05-06

申请号：US13712306

申请日：2012-12-12

Applicant: Apple Inc.

Inventor： Ali Motamed

IPC: H03M1/78

CPC classification number: H03M1/0682 ,  H03M1/682 ,  H03M1/765

Abstract: A differential digital-to-analog converter (DAC) is disclosed. In one embodiment, a DAC includes a number of resistor networks coupled in series to form a ring, and a digital decoder configured to receive a digital code. Based on the most significant bits of the digital code, the digital decoder is configured to close selected ones of first and second groups of switches to couple first and second reference voltage nodes to corresponding tap points on the ring. Within the number of networks are first and second output circuits, each of which is arranged as a one-hot multiplexer. Based on the least significant bits of the digital code, the decoder is configured to couple respective tap points in the ring to first and second output voltage nodes in order to provide a differential output voltage based on the digital code.

Abstract translation: 公开了差分数模转换器（DAC）。 在一个实施例中，DAC包括串联耦合以形成环的多个电阻网络，以及被配置为接收数字码的数字解码器。 基于数字代码的最高有效位，数字解码器被配置为关闭第一和第二组开关中的选定的开关，以将第一和第二参考电压节点耦合到环上的相应抽头点。 网络数量是第一和第二输出电路，其中每一个被布置为单热复用器。 基于数字代码的最低有效位，解码器被配置为将环中的各个抽头点耦合到第一和第二输出电压节点，以便基于数字代码提供差分输出电压。

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.