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US 7,948,314 B2Granted
Tunable linear operational transconductance amplifier
AssigneeSTMicroelectronics (Shenzhen) R&D Co. Ltd
InventorsKunkun Zheng, Jianhua Zhao
Life of this patent
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Abstract
A tunable, linear operational transconductance amplifier includes a differential voltage to current conversion unit adapted to generate first and second output signals at respective first and second output nodes responsive to first and second differential input signals. A first current amplification unit is adapted to generate a third output signal responsive to the first output signal and first and second control signals. A second current amplification unit is adapted to generate a fourth output signal responsive to the second output signal and the first and second control signals.
Claims22
A tunable, linear operational transconductance amplifier, comprising:
- a differential voltage to current conversion unit adapted to generate first and second current signals at respective first and second nodes responsive to first and second differential input signals, wherein the differential voltage to current conversion unit includes first and second operational amplifiers each having a first input terminal adapted to receive the first and second differential input signals, respectively, and each having a second input terminal coupled to the first and second nodes, respectively;
- a resistor coupled between the first and second nodes;
- a first current amplification unit adapted to generate a first output signal responsive to the first current signal and first and second control signals;
- and
- a second current amplification unit adapted to generate a second output signal responsive to the second current signal and the first and second control signals.
2 more elements
A tunable operational transconductance amplifier, comprising:
- a differential voltage to current conversion unit adapted to generate first and second output signals at respective first and second output nodes responsive to first and second differential input signals;
- a first current amplification unit adapted to generate a third output signal responsive to the first output signal and first and second control signals;
- and
- a second current amplification unit adapted to generate a fourth output signal responsive to the second output signal and the first and second control signals;
- wherein a transconductance of the amplifier is represented by the following equation:
- Gm=K*(VX/VY),
- where Gm is the transconductance, K is a constant, and VX and VY are the first and second control signals, respectively.
4 more elements
A tunable operational transconductance amplifier, comprising:
- a first operational amplifier having an input terminal adapted to receive a first differential input signal;
- a second operational amplifier having an input terminal adapted to receive a second differential input signal;
- a first transistor coupled to the first operational amplifier and adapted to generate a first output signal at a first output node;
- a second transistor coupled to the second operational amplifier and adapted to generate a second output signal at a second output node;
- a resistor coupled between the first and second output nodes;
- a first current amplifier adapted to generate a third output signal responsive to the first output signal and first and second control signals;
- and
- a second current amplifier adapted to generate a fourth output signal responsive to the second output signal and the first and second control signals.
5 more elements
A tunable operational transconductance amplifier, comprising:
- a voltage to current converter adapted to receive a differential input voltage and output at first and second nodes first and second currents responsive thereto;
- a resistor coupled between the first and second nodes;
- a first circuit adapted to receive the first current at the first node and output a third current amplified in response to first and second control voltages, the first circuit comprising a first current mirror circuit having a first leg including a voltage to current converter receiving the first control voltage and a second leg mirrored to the first leg and including a voltage to current converter receiving the second control voltage;
- and
- a second circuit adapted to receive the second current at the second node and output a fourth current amplified in response to the first and second control voltages, the second circuit comprising a second current mirror circuit having a first leg including a voltage to current converter receiving the first control voltage and a second leg mirrored to the first leg and including a voltage to current converter receiving the second control voltage.
2 more elements
A tunable operational transconductance amplifier, comprising:
- a voltage to current converter adapted to receive a differential input voltage and output first and second currents responsive thereto;
- a first circuit adapted to receive the first current and output a third current amplified in response to first and second control voltages;
- and
- a second circuit adapted to receive the second current and output a fourth current amplified in response to the first and second control voltages;
- wherein a ratio of the third current to the first current, and a ratio of the fourth current to the second current, is given by a ratio of the first voltage to the second voltage.
2 more elements
A tunable operational transconductance amplifier, comprising:
- a voltage to current converter adapted to receive a differential input voltage and output first and second currents responsive thereto;
- a first circuit adapted to receive the first current and output a third current amplified in response to first and second control voltages;
- and
- a second circuit adapted to receive the second current and output a fourth current amplified in response to the first and second control voltages;
- wherein the voltage to current converter includes a transconductance resistor and wherein a transconductance of the amplifier is defined by K*(VX/VY), where K is a constant, and VX and VY are first and second control voltages, respectively.
2 more elements
Dependencies are inferred from the claim text.