公开(公告)号：EP2507908A1

公开(公告)日：2012-10-10

申请号：EP09806055.1

申请日：2009-11-30

Applicant: St-Ericsson India Pvt. Ltd. ,  ST-Ericsson SA

Inventor： SEEDHER, Ankit ,  PRABHU J, Raja ,  SOMAYAJULA S, Shyam

IPC: H03F1/30 ,  H03F3/217

CPC classification number: H03F3/217 ,  H03F1/305

Abstract: A device implementing a scheme for reduction of pop-up noise is disclosed. The device comprises an audio subsystem (100) having an integrator (112) for amplifying an input signal (133) and a modulation circuit (114) including one or more comparators. The audio subsystem (100) is further provided with a feedback loop (142) across the integrator (112) and the modulation circuit (114) to calibrate an offsets outputs of the integrator (112) and the modulation circuit (114). The feedback loop (142) includes an integrator-offset loop (202) across the integrator (112) to calibrate an offset (136) in the output of the integrator (112), and an offset calibration loop (302) across the modulation circuit (114) to calibrate an offset (140) in the output of the modulation circuit (114).

Abstract translation: 公开了实现用于减少弹出噪声的方案的设备。 该设备包括具有用于放大输入信号（133）的积分器（112）和包括一个或多个比较器的调制电路（114）的音频子系统（100）。 音频子系统（100）还在积分器（112）和调制电路（114）上设置有反馈回路（142），以校准积分器（112）和调制电路（114）的偏移输出。 反馈环路（142）包括跨越积分器（112）的积分器偏移环路（202）以校准积分器（112）的输出中的偏移（136），以及越过调制电路（112）的偏移校准环路（302） （114）校准调制电路（114）的输出中的偏移（140）。

公开(公告)号：EP2486651A1

公开(公告)日：2012-08-15

申请号：EP10788409.0

申请日：2010-10-08

Applicant: St-Ericsson India Pvt. Ltd. ,  ST-Ericsson SA

Inventor： SOMAYAJULA, Shyam S. ,  SEEDHER, Ankit ,  PRABHU, Raja J.

IPC: H03F3/217 ,  H03K7/08 ,  H03F1/26

CPC classification number: H03F3/2173 ,  H03F1/26 ,  H03F2200/03 ,  H03F2200/33 ,  H03F2200/351 ,  H03F2200/384 ,  H03K7/08

Abstract: A device and a method for implementing pulse width modulation for switching amplifiers (120) is described herein. In one embodiment, the device includes a sampling signal generator (202) to generate a sampling signal (208) and a modulation unit (102) operatively coupled to the sampling signal generator (202). The modulation unit (102) generates differential pulse width modulated waveforms based on the sampling signal (208) and differential input signals (220-1 and 220-2) such that at least one differential pulse width modulated waveform has a duty cycle equivalent to a pre-determined non-zero minimum pulse width at all values of the differential input signals (220-1 and 220-2).