The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 05, 2016
Filed:
Mar. 06, 2014
Stmicroelectronics (Shenzhen) R&d Co. Ltd., Shenzhen, CN;
Ru Feng Du, Shenzhen, CN;
Qi Yu Liu, Shenzhen, CN;
STMicroelectronics (Shenzhen) R&D Co. Ltd, Shenzhen, CN;
Abstract
A Class-D amplifier includes a pre-amplifier having an input configured to receive an amplifier reference voltage signal which is ramped at start-up at a fast rate. An integrator has a first input configured to receive an input signal from the pre-amplifier and a second input configured to receive an integrator reference voltage signal which is ramped at start-up at a slower rate. A modulator has an input coupled to an output of the integrator. The modulator generates a pulse width modulated output signal. Operation of the Class-D amplifier is controlled at start-up by applying a slow ramped signal as the integrator reference voltage signal and a fast ramped signal as the amplifier reference voltage so that the pulse width modulated output signal exhibits an increasing change in duty cycle in response to an increasing voltage of the integrator reference voltage signal, and no 'pop' is introduced at start-up.