公开(公告)号：US12212237B2

公开(公告)日：2025-01-28

申请号：US17974787

申请日：2022-10-27

Applicant: Apple Inc.

Inventor： Michael Couleur ,  Bogdan-Eugen Matei ,  Ming Sun ,  Bhanupriya Suresh

IPC: H02M3/158 ,  H03M1/10

Abstract: The present disclosure describes a system with a first counter circuit, a first converter circuit, a second counter circuit, and a second converter circuit. The first counter circuit is configured to output a first count value based on a comparison between a first reference value and a switched node value of a voltage regulator. The first converter circuit is configured to adjust an activation time of the voltage regulator based on the first count value. The second counter circuit is configured to output a second count value based on a comparison between a second reference value and the switched node value of the voltage regulator. The second converter circuit is configured to adjust an amount of current drawn away from an output of the voltage regulator based on the second count value.

公开(公告)号：US20240429931A1

公开(公告)日：2024-12-26

申请号：US18338956

申请日：2023-06-21

Applicant: Apple Inc.

Inventor： Nicola Rasera ,  Cristian Grecu ,  Bogdan-Eugen Matei ,  Fabio Ongaro ,  Ming Sun

IPC: H03M1/10

Abstract: A piecewise linear current-mode digital-to-analog converter circuit approximates an exponential output current over a range of input codes by generating linearly varying currents with different slopes of different ranges of the input codes. The piecewise linear current-mode digital-to-analog converter circuit includes a current generator circuit that generates the output current based on a reference voltage and a feedback signal. A variable resistance circuit is used to generate the feedback signal using the output current. Respective values of the reference voltage and the variable resistance circuit vary as a function of the input code.

公开(公告)号：US20240096291A1

公开(公告)日：2024-03-21

申请号：US18243011

申请日：2023-09-06

Applicant: Apple Inc.

Inventor： Ming Sun ,  Nicola Rasera ,  Robert D Zucker ,  Johan L Piper ,  Denis M Darmon ,  Fabio Ongaro ,  Xiaofeng Wang

IPC: G09G3/34

CPC classification number: G09G3/3413 ,  G09G3/346 ,  G09G2320/0209 ,  G09G2320/0247 ,  G09G2330/021

Abstract: Systems and methods for electronic displays to use reference voltages to control driving current of illuminators are provided. The reference voltages are used to reduce or eliminate cross talk in driving voltages among different illuminators and driving voltage variations from frame to frame. The transient performance of the driving current of the illuminator (e.g., the current rise/decline time, current overshoot issue, current settling time) may be improved by implementing the reference voltages.