Invention Grant
US09391577B2 Low-voltage analog variable gain amplifier with enhanced linearity
有权
具有增强线性度的低压模拟可变增益放大器
- Patent Title: Low-voltage analog variable gain amplifier with enhanced linearity
- Patent Title (中): 具有增强线性度的低压模拟可变增益放大器
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Application No.: US14670031Application Date: 2015-03-26
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Publication No.: US09391577B2Publication Date: 2016-07-12
- Inventor: Petrus M. Stroet
- Applicant: Linear Technology Corporation
- Applicant Address: US CA Milpitas
- Assignee: Linear Technology Corporation
- Current Assignee: Linear Technology Corporation
- Current Assignee Address: US CA Milpitas
- Agency: Patent Law Group LLP
- Agent Brian D. Ogonowsky
- Main IPC: H03F3/45
- IPC: H03F3/45 ; H03G3/00 ; H03G3/30 ; H03F1/02 ; H03F3/19 ; H04L27/34 ; H03F1/32 ; H03G1/00

Abstract:
In a variable gain amplifier, a base of a bipolar first transistor receives a first differential input signal. The emitter of the first transistor is connected in series between a first resistor and a MOSFET coupled to ground. An output of the amplifier is a current through the collector. The conductivity of the MOSFET controls a gain of the amplifier. A bipolar second transistor receives a second differential input signal, and the second transistor provides a modulated gate voltage to the MOSFET. The drain voltage of the MOSFET is modulated by the first differential input signal and thus undesirably generates distortion. To reduce the distortion, the modulated gate voltage causes the AC component for a certain DC voltage at the drain of the MOSFET to be lowered, improving linearity. Since no current source is used, the amplifier has a large headroom, allowing operation using a low operating voltage.
Public/Granted literature
- US20150326198A1 LOW-VOLTAGE ANALOG VARIABLE GAIN AMPLIFIER WITH ENHANCED LINEARITY Public/Granted day:2015-11-12
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