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公开(公告)号：US10269307B2
公开(公告)日：2019-04-23
申请号：US15683648
申请日：2017-08-22
Applicant: Apple Inc.
Inventor： Yanhui Xie , Asif Hussain , Jingdong Chen , Mohammad J. Navabi-Shirazi
Abstract: Aspects of the subject technology relate to control circuitry for operating light-emitting diodes (LEDs). The control circuitry may include a pulse-width-modulation (PWM) driver for the LEDs and headroom voltage control circuitry. The PWM driver may adjust a rising edge or a trailing edge of the PWM cycles for various LEDs to ensure a headroom voltage detection window for the headroom voltage control circuitry to sample the headroom voltage of those LEDs without being affected by the rising edge of the PWM cycle for LED or the falling edge of the PWM cycle for another LED.
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公开(公告)号：US20200105185A1
公开(公告)日：2020-04-02
申请号：US16418882
申请日：2019-05-21
Applicant: Apple Inc.
Inventor： Jingdong Chen , Asif Hussain , Mohammad J. Navabi-Shirazi , Behzad Mohtashemi , Yanhui Xie , JY Ryoo , Ming Gu
Abstract: A display may have an array of pixels illuminated using a backlight unit. The backlight unit may include multiple strings of light-emitting diodes (LEDs) and a boost converter for providing an output voltage to the multiple LED strings. The boost converter may have a single-phase single-switch, single-phase multi-switch, and/or multi-phase multi-switch configuration, where the switches are turned off when the peak current is reached. When transitioning from a single phase to a dual phase operation, the second (slave) phase current may be slowly ramped up. When transition from the dual phase to the single phase operation, the output voltage may be elevated while slowing ramping down the slave phase current. The boost converter may include a current detection circuit for adjusting the peak current of each phase to balance the average current levels. The boost converter may also include an in-rush current controller configured to sense a short fault.
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公开(公告)号：US20160329820A1
公开(公告)日：2016-11-10
申请号：US15148870
申请日：2016-05-06
Applicant: Apple Inc.
Inventor： Behzad Mohtashemi , Asif Hussain , Manisha P. Pandya , Mohammad J. Navabi-Shirazi , Nileshbhai J. Shah
CPC classification number: H02M3/33523 , H02M1/32 , H02M2001/0009
Abstract: Various systems and methods are disclosed herein, which provide isolated systems with an auxiliary, multi-signal digital feedback loop for reporting a plurality of different potential fault conditions in an output system (e.g., output short circuit, output over-voltage, output under-voltage, output over temperature, etc.) to a Primary Controller in an input system. The signals may be sent according to any desired standardized (or proprietary) data transmission protocols. Use of a digital feedback loop allows the signals to be passed to the Primary Controller more quickly than is allowed by traditional analog feedback paths—and while using only a single optocoupler device for the transmission of all fault conditions. The techniques disclosed herein are applicable to any number of isolated systems that supply power to electronic systems such as: digital cameras, mobile phones, watches, personal data assistants (PDAs), portable music players, monitors, as well as desktop, laptop, and tablet computers.
Abstract translation: 本文公开了各种系统和方法，其为隔离系统提供辅助的多信号数字反馈回路，用于在输出系统中报告多个不同的潜在故障状况（例如，输出短路，输出过压， 电压，输出温度等）输入到输入系统中的主控制器。 可以根据任何期望的标准化（或专有）数据传输协议发送信号。 数字反馈回路的使用允许信号比传统的模拟反馈路径更快地传递到主控制器，而在仅使用单个光耦合器件来传输所有故障条件时。 本文公开的技术适用于向电子系统供电的任何数量的隔离系统，例如：数码相机，移动电话，手表，个人数据助理（PDA），便携式音乐播放器，监视器以及桌面，膝上型计算机和 平板电脑
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公开(公告)号：US20160276928A1
公开(公告)日：2016-09-22
申请号：US15050152
申请日：2016-02-22
Applicant: Apple Inc.
Inventor： Behzad Mohtashemi , Asif Hussain , Manisha P. Pandya , Mohammad J. Navabi-Shirazi , Nileshbhai J. Shah
IPC: H02M3/156
CPC classification number: H02M3/156 , H02M2003/1566
Abstract: A power conversion circuit, such as a buck converter/regulator, includes a feedback loop operatively coupling the output voltage to the controller for the switching mechanism. The feedback loop includes an analog error amplifier that sources current to the controller when the output voltage falls below a predetermined reference voltage and sinks current from the controller when the output voltage rises above a predetermined reference voltage. The feedback loop further includes at least one of a sinking boost circuit that sinks additional current from the controller when the output voltage falls below a low voltage threshold or a sourcing boost circuit that sources additional current to the controller when the output voltage rises above a high voltage threshold. The boost circuits can include analog amplifiers, digital comparators, or a combination thereof.
Abstract translation: 诸如降压转换器/调节器的功率转换电路包括将输出电压可操作地耦合到用于开关机构的控制器的反馈回路。 反馈回路包括模拟误差放大器，当输出电压下降到低于预定参考电压时，向输入电压发送电流，并在输出电压升高到高于预定参考电压时从控制器吸收电流。 所述反馈回路还包括吸收升压电路中的至少一个，当所述输出电压下降到低电压阈值以下或者当所述输出电压升高到高于所述控制器的时候向所述控制器提供额外电流的源极升压电路，所述吸收升压电路吸收来自所述控制器的附加电流 电压阈值。 升压电路可以包括模拟放大器，数字比较器或其组合。
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公开(公告)号：US09185768B2
公开(公告)日：2015-11-10
申请号：US13940181
申请日：2013-07-11
Applicant: Apple Inc.
Inventor： Mohammad J. Navabi-Shirazi , Asif Hussain , Jingdong Chen , Manisha P. Pandya
CPC classification number: H05B33/0887 , G06F1/26 , H02M3/156 , H02M2001/0025 , H05B33/0815 , H05B33/0884 , Y02B20/341
Abstract: A measured voltage drop across a power-line transistor is used as a sensing element to measure the current and detect an over-current condition for an LED backlight system. An over-current or short condition is detected when the measured voltage drop exceeds a threshold. Accurate detection of the over-current condition is achieved by calibrating the RDS-ON (i.e., internal resistance between drain and source, when transistor is on) of the power-line transistor. In one embodiment, the calibration of RDS-ON is performed by ramping down the threshold from an initial value and using the tripped threshold to determine the actual value for RDS-ON. In another embodiment, the calibration of RDS-ON is performed by using two thresholds, a first threshold to calibrate RDS-ON and a second threshold to detect the over-current condition.
Abstract translation: 电力线晶体管两端的测量电压降被用作传感元件，以测量电流并检测LED背光系统的过电流状态。 当测量的电压降超过阈值时，检测到过电流或短路状况。 通过校准电源线晶体管的RDS-ON（即，在晶体管导通时漏极和源极之间的内部电阻）来实现过电流状态的精确检测。 在一个实施例中，RDS-ON的校准是通过从初始值降低阈值并使用跳闸阈值来确定RDS-ON的实际值来执行的。 在另一个实施例中，通过使用两个阈值来执行RDS-ON的校准，第二阈值是用于校准RDS-ON的第一阈值和用于检测过电流状态的第二阈值。
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Patent Agency Ranking
公开(公告)号：US08970200B2
公开(公告)日：2015-03-03
申请号：US13673695
申请日：2012-11-09
Applicant: Apple Inc.
Inventor： Asif Hussain , Jingdong Chen , Manisha P. Pandya , Mohammad J. Navabi-Shirazi
CPC classification number: G09G5/10 , G09G3/3406 , G09G2300/0426 , G09G2320/0233
Abstract: Systems and methods for light-load efficiency in displays may include a backlight driver circuit that may adjust a gate drive voltage provided to a gate of a metal-oxide-semiconductor field-effect transistor (MOSFET) in the boost converter based on the load conditions of light-emitting diodes used to illuminate the display panel. The backlight driver circuit may also switch between two different voltage sources to further broaden a range of gate drive voltages available to drive the gate of the MOSFET in the boost converter. As a result, the backlight driver circuit may decrease gate drive losses associated with the MOSFET, thereby increasing the efficiency of the boost converter.
Abstract translation: 显示器中轻负载效率的系统和方法可以包括背光驱动器电路，其可以基于负载条件来调节提供给升压转换器中的金属氧化物半导体场效应晶体管（MOSFET）的栅极的栅极驱动电压 的用于照亮显示面板的发光二极管。 背光驱动器电路还可以在两个不同的电压源之间切换，以进一步扩大可用于驱动升压转换器中的MOSFET的栅极的栅极驱动电压的范围。 结果，背光驱动器电路可以减小与MOSFET相关联的栅极驱动损耗，从而提高升压转换器的效率。
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公开(公告)号：US10383186B2
公开(公告)日：2019-08-13
申请号：US15785082
申请日：2017-10-16
Applicant: Apple Inc.
Inventor： Yanhui Xie , Asif Hussain , Ji Yeoul Ryoo , Jingdong Chen , Mohammad J. Navabi-Shirazi
IPC: H05B33/08 , G02F1/13357 , G02F1/1335
Abstract: Aspects of the subject technology relate to control circuitry for light-emitting diodes. The control circuitry may include a feedforward loop and a feedback loop for a power supply for the light-emitting diodes. The light-emitting diodes may be arranged in strings that are individually controllable by a current control transistor on the string. The feedforward loop may determine a total upcoming load current for the power supply based on reference voltages for controlling each of the current control transistors. The output of the power supply may be modified based on a combination of a current from the feedforward loop and a current from the feedback loop.
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公开(公告)号：US20190215924A1
公开(公告)日：2019-07-11
申请号：US16353896
申请日：2019-03-14
Applicant: Apple Inc.
Inventor： Mohammad J. Navabi-Shirazi , Alejandro Lara Ascorra , Asif Hussain , Ji Yeoul Ryoo , Jingdong Chen , Jun Qi , Manisha P. Pandya , Yanhui Xie
Abstract: Aspects of the subject technology relate to control circuitry for light-emitting diodes. The control circuitry may operate a light-emitting diode using a multi-peak pulse-width-modulation signal. The control circuitry may include a multi-stage driver having a relatively larger driver stage for providing a direct current through a light-emitting diode and a relatively smaller driver stage configured to cooperate with a pulse-width-modulation controller to pulse-width-modulate a current through the light-emitting diode.
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公开(公告)号：US20160329830A1
公开(公告)日：2016-11-10
申请号：US15148245
申请日：2016-05-06
Applicant: Apple Inc.
Inventor： Asif Hussain , Behzad Mohtashemi , Manisha P. Pandya , Mohammad J. Navabi-Shirazi
CPC classification number: H02M7/537 , H02M1/08 , H02M3/158 , H02M2001/0009 , H02M2001/0058 , Y02B70/1425 , Y02B70/1483 , Y02B70/1491
Abstract: Various systems, apparatuses, and methods are disclosed herein, which provide a new power conversion topology for isolated systems that does not include a transformer. Embodiments of the inventive systems comprise: a switching system utilizing high voltage, low leakage switches, e.g., Silicon Carbide (SiC) MOS-FETs; a power source; an inductor and a capacitor operating as a link stage resonant LC circuit; and a load. The switching system may be configured to be controlled in a synchronized ‘four phase’ control loop process, wherein the input switches are prevented from being closed at the same time as the output switches, thereby providing electrical isolation between the input power source and the load—without the use of a transformer. The techniques disclosed herein are applicable to any number of isolated systems that supply power to electronic systems such as: digital cameras, mobile phones, watches, personal data assistants (PDAs), portable music players, displays, and computers.
Abstract translation: 本文公开了各种系统，装置和方法，其为不包括变压器的隔离系统提供新的功率转换拓扑。 本发明系统的实施例包括：利用高电压，低泄漏开关（例如碳化硅（SiC））MOS-FET的开关系统; 电源; 作为链路级谐振LC电路的电感器和电容器; 和一个负载。 开关系统可以被配置为被控制在同步的“四相”控制环路过程中，其中防止输入开关与输出开关同时闭合，从而在输入电源和负载之间提供电隔离 - 不使用变压器。 本文公开的技术适用于向诸如数字照相机，移动电话，手表，个人数据助理（PDA），便携式音乐播放器，显示器和计算机之类的电子系统供电的任何数量的隔离系统。
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公开(公告)号：US20140139143A1
公开(公告)日：2014-05-22
申请号：US13940181
申请日：2013-07-11
Applicant: Apple Inc.
Inventor： Mohammad J. Navabi-Shirazi , Asif Hussain , Jingdong Chen , Manisha P. Pandya
IPC: H05B33/08
CPC classification number: H05B33/0887 , G06F1/26 , H02M3/156 , H02M2001/0025 , H05B33/0815 , H05B33/0884 , Y02B20/341
Abstract: A measured voltage drop across a power-line transistor is used as a sensing element to measure the current and detect an over-current condition for an LED backlight system. An over-current or short condition is detected when the measured voltage drop exceeds a threshold. Accurate detection of the over-current condition is achieved by calibrating the RDS-ON (i.e., internal resistance between drain and source, when transistor is on) of the power-line transistor. In one embodiment, the calibration of RDS-ON is performed by ramping down the threshold from an initial value and using the tripped threshold to determine the actual value for RDS-ON. In another embodiment, the calibration of RDS-ON is performed by using two thresholds, a first threshold to calibrate RDS-ON and a second threshold to detect the over-current condition.
Abstract translation: 电力线晶体管两端的测量电压降被用作传感元件，以测量电流并检测LED背光系统的过电流状态。 当测量的电压降超过阈值时，检测到过电流或短路状况。 通过校准电源线晶体管的RDS-ON（即，在晶体管导通时漏极和源极之间的内部电阻）来实现过电流状态的精确检测。 在一个实施例中，RDS-ON的校准是通过从初始值降低阈值并使用跳闸阈值来确定RDS-ON的实际值来执行的。 在另一个实施例中，通过使用两个阈值来执行RDS-ON的校准，第二阈值是用于校准RDS-ON的第一阈值和用于检测过电流状态的第二阈值。
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