公开(公告)号：US20170250654A1

公开(公告)日：2017-08-31

申请号：US15443503

申请日：2017-02-27

Applicant: QUALCOMM Incorporated

Inventor： William COPE

IPC: H03F1/02 ,  H03F3/217 ,  H03F3/185

CPC classification number: H03F3/185 ,  H03F3/217 ,  H03F3/2171 ,  H03F3/2173 ,  H03F2200/03 ,  H03F2200/102 ,  H03F2200/351 ,  H03F2200/391 ,  H03F2200/78 ,  H03K17/165

Abstract: Certain aspects of the present disclosure provide methods and apparatus for dynamically managing the dead time between turning on output power stage transistors in amplifiers, such as audio amplifiers. One example method of operating an amplifier generally includes generating a drive signal based on an input signal; amplifying the drive signal by alternatively driving a first transistor and a second transistor with a time between deactivating the first transistor and activating the second transistor; and adjusting the time based on a parameter of the input signal or the drive signal, during the amplifying. For example, the parameter may include an amplitude of the input signal, a duty cycle of the drive signal, or a duty cycle of a modulated signal (e.g., a pulse-width modulated signal) generated based on the input signal. The input signal may be a digital audio input signal.

公开(公告)号：US20170250662A1

公开(公告)日：2017-08-31

申请号：US15443889

申请日：2017-02-27

Applicant: QUALCOMM Incorporated

Inventor： William COPE ,  Julian ASCHIERI ,  Tomer SARAF

IPC: H03F3/26 ,  H03F3/187

CPC classification number: H03F3/187 ,  H03F1/523 ,  H03F3/185 ,  H03F3/2173 ,  H03F3/45475 ,  H03F2200/03 ,  H03F2200/331 ,  H03F2200/426 ,  H03F2200/78 ,  H03F2203/45514 ,  H03M3/49 ,  H03M3/492

Abstract: Certain aspects of the present disclosure provide amplifiers. Certain aspects of the present disclosure provide methods and apparatus for protecting an such amplifiers, for example an audio amplifier, or a delta-sigma modulator from saturation. One example amplifier generally includes an output stage comprising a plurality of transistors; and a feedback network having an input coupled to an output of the output stage and comprising a plurality of integrators connected in series. At least one of the plurality of integrators generally includes an operational amplifier having an input and an output, a first resistive element coupled to the input of the operational amplifier, a capacitive element coupled between the input and the output of the operational amplifier; and a first switch coupled between the input and the output of the operational amplifier. For certain aspects, the amplifier may be a class-D amplifier or a direct digital feedback amplifier (DDFA).

公开(公告)号：US20170250655A1

公开(公告)日：2017-08-31

申请号：US15444021

申请日：2017-02-27

Applicant: QUALCOMM Incorporated

Inventor： William COPE ,  Jieting SUN ,  Donald GEE

IPC: H03F1/02 ,  H03G3/30 ,  H03F1/52 ,  H04R3/00 ,  H03F3/185 ,  H03F3/217

CPC classification number: H03F1/0233 ,  H03F1/523 ,  H03F3/185 ,  H03F3/217 ,  H03F3/2171 ,  H03F3/2173 ,  H03F2200/03 ,  H03F2200/351 ,  H03F2200/391 ,  H03F2200/426 ,  H03G7/002 ,  H03G7/08 ,  H04R3/007 ,  H04R2430/01

Abstract: Certain aspects of the present disclosure provide an amplifier for signal amplification. Certain aspects further describe methods and apparatus for applying overload protection for such amplifier. For example, one method generally includes detecting an overload condition of an amplifier based on a signal at a node of the amplifier, and controlling a parameter of an input signal of the amplifier such that the parameter of the input signal is maintained below a threshold based on the detection of the overload condition. The parameter of the input signal may include, for example, a voltage level or a duty cycle of the input signal.