公开(公告)号：US09425741B2

公开(公告)日：2016-08-23

申请号：US14692293

申请日：2015-04-21

Applicant: Stryker Combo L.L.C.

Inventor： Regis J Nero, Jr. ,  Jeffrey A Gibala

IPC: H03F1/02 ,  H03F3/24 ,  H03F3/19 ,  H03F3/217 ,  H02M1/00

CPC classification number: H03F1/0227 ,  H02M2001/0045 ,  H03C1/02 ,  H03F1/02 ,  H03F3/19 ,  H03F3/217 ,  H03F3/2176 ,  H03F3/245 ,  H03F2200/324 ,  H03F2200/451

Abstract: Systems and methods are provided for generating an amplitude modulation signal to a switchmode power amplifier. A DC to DC switch is configured to receive a DC input voltage and to provide a DC output voltage. A low dropout regulator is configured to provide the amplitude modulation signal according to a modulation control signal received by the low dropout regulator. A control circuit is configured to establish a nominal operating power level for the power amplifier via the amplitude modulation signal and to maintain a minimum voltage difference between the DC output voltage and the low dropout regulator output. A modulator control circuit is configured to provide the modulation control signal to the low dropout regulator. The modulator control circuit provides the transition from a high amplitude to a low amplitude and a transition from the low amplitude to the high amplitude at configurable first and second slopes, respectively.