Invention Grant
US08976981B2 Circuit, system and method for isolating a transducer from an amplifier in an electronic device
有权
用于将换能器与电子设备中的放大器隔离的电路,系统和方法
- Patent Title: Circuit, system and method for isolating a transducer from an amplifier in an electronic device
- Patent Title (中): 用于将换能器与电子设备中的放大器隔离的电路,系统和方法
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Application No.: US12900061Application Date: 2010-10-07
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Publication No.: US08976981B2Publication Date: 2015-03-10
- Inventor: Jens Kristian Poulsen , Mohamad El-Hage
- Applicant: Jens Kristian Poulsen , Mohamad El-Hage
- Applicant Address: CA Waterloo, Ontario
- Assignee: BlackBerry Limited
- Current Assignee: BlackBerry Limited
- Current Assignee Address: CA Waterloo, Ontario
- Agency: McCarthy Tétrault LLP
- Main IPC: H03G3/00
- IPC: H03G3/00 ; H03F1/00 ; H03F3/187

Abstract:
A circuit, device and method for controlling an output signal of an amplifier are provided. The output signal may be controlled through a first stage located before a digital to analog converter and/or a second stage located after it. The first stage boosts the digital signal to match with the full signal range of the converter. For the second stage, the circuit comprises: a first resistor coupled to an output of the amplifier in series, the first resistor having a resistance value Rs; a second resistor coupled to the first resistor in series, the second resistor having a resistance value Rp; and an output terminal for a transducer connected to the electronic device, the output terminal connected in parallel to the second resistor. In the circuit, the resistance values Rs and Rp are related by an inversely proportional relationship. The circuit provides an output signal at the output terminal having a noise floor that varies with an output level of the amplifier and a constant output impedance as seen from the transducer.
Public/Granted literature
- US20120087515A1 CIRCUIT, SYSTEM AND METHOD FOR ISOLATING A TRANSDUCER FROM AN AMPLIFIER IN AN ELECTRONIC DEVICE Public/Granted day:2012-04-12
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