Active load generation circuit and filter using same
First Claim
1. An active load generation circuit comprising:
- a transistor that provides an impedance and has a control terminal and an input terminal, wherein the control terminal receives a control voltage, the input terminal receives an input signal, and the impedance is related to the control voltage;
a voltage control circuit configured to generate an intermediate voltage according to a power supply voltage and a first reference voltage;
a voltage offset and tracking circuit coupled between the voltage control circuit and the transistor and configured to generate the control voltage according to the input signal and the intermediate voltage, wherein the control voltage varies with the input signal; and
a temperature sensing circuit coupled to the voltage control circuit and configured to sense an ambient temperature of the active load generation circuit and adjust the first reference voltage according to the ambient temperature.
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Accused Products
Abstract
This invention discloses an active load generation circuit and a filter. The active load generation circuit includes a transistor, a voltage control circuit, a voltage offset and tracking circuit, and a temperature sensing circuit. The transistor provides an impedance and includes a control terminal and an input terminal. The control terminal receives a control voltage, the input terminal receives an input signal, and the impedance is associated with the control voltage. The voltage control circuit generates an intermediate voltage according to a power supply voltage and a first reference voltage. The voltage offset and tracking circuit generates the control voltage according to the input signal and the intermediate voltage such that the control voltage varies with the input signal. The temperature sensing circuit senses an ambient temperature of the active load generation circuit and adjusts the first reference voltage according to the ambient temperature.
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Citations
17 Claims
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1. An active load generation circuit comprising:
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a transistor that provides an impedance and has a control terminal and an input terminal, wherein the control terminal receives a control voltage, the input terminal receives an input signal, and the impedance is related to the control voltage; a voltage control circuit configured to generate an intermediate voltage according to a power supply voltage and a first reference voltage; a voltage offset and tracking circuit coupled between the voltage control circuit and the transistor and configured to generate the control voltage according to the input signal and the intermediate voltage, wherein the control voltage varies with the input signal; and a temperature sensing circuit coupled to the voltage control circuit and configured to sense an ambient temperature of the active load generation circuit and adjust the first reference voltage according to the ambient temperature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An active load generation circuit comprising:
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a first transistor that provides an impedance and has a first control terminal, wherein the first control terminal receives a control voltage, and the impedance is related to the control voltage; a voltage control circuit coupled to the first transistor and configured to generate the control voltage according to a power supply voltage and a first reference voltage, the voltage control circuit comprising; a second transistor having a second control terminal and a first output terminal, wherein the first output terminal outputs the control voltage; a plurality of resistors connected in series between the second transistor and the power supply voltage, or between the second transistor and a second reference voltage; and an operational amplifier having a first input terminal, a second input terminal, and a second output terminal, wherein the first input terminal receives the first reference voltage, the second input terminal is coupled to the resistors, and the second output terminal is coupled to the second control terminal; and a temperature sensing circuit coupled to the voltage control circuit and configured to sense an ambient temperature of the active load generation circuit and adjust the first reference voltage according to the ambient temperature. - View Dependent Claims (10, 11, 12, 13)
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14. An active load generation circuit comprising:
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a transistor that provides an impedance and has a control terminal, wherein the control terminal receives a control voltage, and the impedance is related to the control voltage; a voltage control circuit coupled to the transistor and configured to generate the control voltage according to a power supply voltage and a first reference voltage; a temperature sensing circuit coupled to the voltage control circuit and configured to sense an ambient temperature of the active load generation circuit and adjust the first reference voltage according to the ambient temperature; a voltage detecting circuit coupled to the voltage control circuit and configured to detect the power supply voltage to generate a control value; wherein the voltage control circuit adjusts the control voltage according to the control value. - View Dependent Claims (15, 16, 17)
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Specification