公开(公告)号：US09300212B2

公开(公告)日：2016-03-29

申请号：US13953317

申请日：2013-07-29

Applicant: Wolfson Microelectronics plc

Inventor： Andrew Notman ,  Mark McCloy-Stevens ,  Douglas James Wallace MacFarlane ,  Holger Haiplik

IPC: H02M3/158 ,  H02M1/00 ,  H02M1/38

CPC classification number: H02M3/1588 ,  H02M1/38 ,  H02M2001/0009 ,  H02M2001/0032 ,  Y02B70/1466

Abstract: Methods and apparatus for control of DC-DC converters, especially in valley current mode. The DC-DC converter is operable so that a low side supply switch may be turned off, before the high side supply switch is turned on. During the period when both switches are off the current loop control remains active and the change in inductor (L) current is emulated. One embodiment uses a current sensor for lossless current sensing and emulates the change in inductor current by holding the value of the output of the current sensor (ISNS) at the time that the low side switch turns off and adding an emulated ramp signal (VISLP) until the inductor current reaches zero. Embodiment employing a pulse-skip mode of operation based on a minimum conduction time are also disclosed. The invention enables a seamless transition from Continuous Conduction Mode the Discontinuous Conduction Mode and Pulse Skipping and provide converters that are efficient at low current loads.

公开(公告)号：US20140307910A1

公开(公告)日：2014-10-16

申请号：US14244075

申请日：2014-04-03

Applicant: Wolfson Microelectronics plc

Inventor： Andrew James Howlett ,  Graeme Gordon MacKay ,  Douglas James Wallace MacFarlane

IPC: H04R3/00

CPC classification number: H04R3/00 ,  H03F3/183 ,  H03F2200/03 ,  H03G3/348 ,  H04R29/004 ,  H04R2420/03 ,  H04R2420/05

Abstract: A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.

Abstract translation: 用于与具有麦克风的可移动外围设备一起使用的主机设备，以及用于所述麦克风的偏置电路。 主机设备可以具有用于与相应的外围连接器形成配合连接的设备连接器。 偏置源被布置成经由偏置路径向设备连接器的设备麦克风接触件提供电偏压。 电容器连接在参考电压节点和偏置路径的电容器节点之间。 第一个开关位于电容器节点和设备麦克风接点之间。 检测电路检测外围连接器和设备连接器的断开; 并且控制电路控制开关以禁用偏置路径。