公开(公告)号：US20210153320A1

公开(公告)日：2021-05-20

申请号：US16908425

申请日：2020-06-22

Applicant: Apple Inc.

Inventor： Cristian Grecu ,  Bogdan-Eugen Matei ,  Angelo Bassi ,  Andrei-Cosmin Gaidam ,  Alessandro Molari

IPC: H05B45/37 ,  H05B45/10 ,  H05B45/44

Abstract: An LED driver circuit is disclosed. The LED driver circuit includes an amplifier having a first input coupled to receive a reference voltage and a second input coupled to receive a feedback voltage. The circuit further includes first and second transistors each having respective gate terminals coupled to an output of the first amplifier. In a first mode, a first switch alternately couples a source terminal of the first transistor to the second input of the amplifier (when the pulse is asserted) and a source terminal of the second transistor to the second input (when the pulse is de-asserted). A third transistor includes a gate terminal that is coupled to ground, by a second switch, when operating in the first mode. When operating in the second mode, the switch couples the third transistor to the output of the amplifier, while the pulse remains asserted.

公开(公告)号：US11594957B2

公开(公告)日：2023-02-28

申请号：US17203567

申请日：2021-03-16

Applicant: Apple Inc.

Inventor： Bogdan-Eugen Matei ,  Cristian Grecu ,  Fabio Ongaro ,  Giovanni Saccomanno ,  Siarhei Meliukh ,  Yesim Inam

IPC: H02M3/07

Abstract: A dual-stage boost converter is disclosed. The boost converter includes a charge pump and a boost stage. The charge pump is coupled between an input voltage source and the boost stage. The charge pump is coupled to receive the input voltage and configured to generate an intermediate voltage that is greater than the input voltage received from the input voltage source. The boost stage includes an inductor coupled to receive the intermediate voltage and is configured to generate an output voltage that is greater than or equal to the intermediate voltage.

公开(公告)号：US20220302826A1

公开(公告)日：2022-09-22

申请号：US17203567

申请日：2021-03-16

Applicant: Apple Inc.

Inventor： Bogdan-Eugen Matei ,  Cristian Grecu ,  Fabio Ongaro ,  Giovanni Saccomanno ,  Siarhei Meliukh ,  Yesim Inam

IPC: H02M3/07

Abstract: A dual-stage boost converter is disclosed. The boost converter includes a charge pump and a boost stage. The charge pump is coupled between an input voltage source and the boost stage. The charge pump is coupled to receive the input voltage and configured to generate an intermediate voltage that is greater than the input voltage received from the input voltage source. The boost stage includes an inductor coupled to receive the intermediate voltage and is configured to generate an output voltage that is greater than or equal to the intermediate voltage.

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：US10694603B1

公开(公告)日：2020-06-23

申请号：US16684567

申请日：2019-11-14

Applicant: Apple Inc.

Inventor： Cristian Grecu ,  Bogdan-Eugen Matei ,  Angelo Bassi ,  Andrei-Cosmin Gaidam ,  Alessandro Molari

IPC: H05B45/10 ,  H05B45/37 ,  H05B45/44

Abstract: An LED driver circuit is disclosed. The LED driver circuit includes an amplifier having a first input coupled to receive a reference voltage and a second input coupled to receive a feedback voltage. The circuit further includes first and second transistors each having respective gate terminals coupled to an output of the first amplifier. In a first mode, a first switch alternately couples a source terminal of the first transistor to the second input of the amplifier (when the pulse is asserted) and a source terminal of the second transistor to the second input (when the pulse is de-asserted). A third transistor includes a gate terminal that is coupled to ground, by a second switch, when operating in the first mode. When operating in the second mode, the switch couples the third transistor to the output of the amplifier, while the pulse remains asserted.

公开(公告)号：US12273977B2

公开(公告)日：2025-04-08

申请号：US18338916

申请日：2023-06-21

Applicant: Apple Inc.

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

IPC: H05B45/30 ,  G05F1/575 ,  H03M7/16 ,  H05B45/34 ,  H05B45/397

Abstract: A high current, low dropout driver circuit is disclosed. The circuit includes a decoder configured to decode a plurality of control bits to generate a plurality of control signals, and a current source having a plurality of devices. The current source is configured to activate at least a subset of the plurality of devices using the control signals to provide a load current to a load circuit, such as a light-emitting diode (LED), using activated ones of the plurality of devices and a control voltage. A control circuit is configured to generate the control voltage based on the load current and a reference current.

公开(公告)号：US20240431001A1

公开(公告)日：2024-12-26

申请号：US18338916

申请日：2023-06-21

Applicant: Apple Inc.

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

IPC: H05B45/397 ,  G05F1/575 ,  H05B45/34

Abstract: A high current, low dropout driver circuit is disclosed. The circuit includes a decoder configured to decode a plurality of control bits to generate a plurality of control signals, and a current source having a plurality of devices. The current source is configured to activate at least a subset of the plurality of devices using the control signals to provide a load current to a load circuit, such as a light-emitting diode (LED), using activated ones of the plurality of devices and a control voltage. A control circuit is configured to generate the control voltage based on the load current and a reference current.

公开(公告)号：US11166355B2

公开(公告)日：2021-11-02

申请号：US16908425

申请日：2020-06-22

Applicant: Apple Inc.

Inventor： Cristian Grecu ,  Bogdan-Eugen Matei ,  Angelo Bassi ,  Andrei-Cosmin Gaidam ,  Alessandro Molari

IPC: H05B45/10 ,  H05B45/37 ,  H05B45/44

Abstract: An LED driver circuit is disclosed. The LED driver circuit includes an amplifier having a first input coupled to receive a reference voltage and a second input coupled to receive a feedback voltage. The circuit further includes first and second transistors each having respective gate terminals coupled to an output of the first amplifier. In a first mode, a first switch alternately couples a source terminal of the first transistor to the second input of the amplifier (when the pulse is asserted) and a source terminal of the second transistor to the second input (when the pulse is de-asserted). A third transistor includes a gate terminal that is coupled to ground, by a second switch, when operating in the first mode. When operating in the second mode, the switch couples the third transistor to the output of the amplifier, while the pulse remains asserted.