Operational transconductance amplifier with DC offset elimination and low mismatch
AssigneeElectronics and Telecommunications Research Institute
InventorsYoung Ho Kim, Mun Yang Park
Life of this patent
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Abstract
Provided is a transconductor capable of eliminating a direct current (DC) offset component of a signal and compensating a mismatch of the signal. The transconductor includes amplifiers of simple circuit structures, and a common mode control DC offset elimination circuit. The transconductor includes a common mode control DC offset elimination circuit unit receiving input/output voltages to stabilize the current supplying and the output DC value, a first amplifier and a second amplifier reducing a mismatch in a transconductor circuit and increasing an output resistance, in order to prevent a signal distortion or a wrong operation of the circuit that is caused by the mismatch signal and unstable DC voltage.
Claims9
A transconductor comprising:
- a transconductor circuit outputting an output voltage that is converted from an input voltage so as to be in proportion to a transconductance;
- and
- a direct current (DC) offset elimination circuit fixing an output DC voltage, which is changed according to a DC offset included in the input voltage, into a common mode voltage of constant magnitude,
- wherein the transconductor circuit including:
- a first transistor having a dual-pair input structure and operating in a triode region;
- a second transistor receiving a node voltage of the first transistor and controlling a drain-source voltage of the first transistor so that the first transistor can operate in the triode region and a first inversion amplifier,
- a third transistor and a second inversion amplifier disposed to increase an output resistance;
- and
- a fourth transistor supplying the electric current that is input from the DC offset elimination circuit by mirroring the current.
Dependencies are inferred from the claim text.