An integrated circuit may include one or more circuits coupled to capacitance multiplier circuitry. The capacitance multiplier circuitry may include a capacitor, fixed and tunable resistances, and a transconductance circuit. The tunable resistance can be adjusted to control the overall capacitance of the capacitance multiplier circuitry. The transconductance circuit may include a transistor having a drain terminal coupled to a first electrical component and a source terminal coupled to a second electrical component. The first electrical component may be a diode-connected transistor, a direct shorting wire, a resistor, an inductor, or a current source. The second electrical component may be a current source, a direct shorting wire, a resistor, an inductor, or another diode-connected device. Configured in this way, the capacitance multiplier circuitry can provide a large adjustable amount of capacitance without a voltage drop and without consuming a large amount of power.

A circuit for controlling a capacitor having a capacitance adjustable by biasing, including an amplifier for delivering a D.C. bias voltage, having a feedback slowed down by a resistive and capacitive cell.

A tunable impedance multiplier with high multiplication factor is described. A single externally connected resistor is used and the multiplier is free of passive elements. The circuit can realize a positive or a negative impedance multiplier. Applications of the design to low and high pass filters are also presented. The simulation and experimental results show that the new design enjoys a multiplication factor above 400 at 2 Hz-to 7 MHz.

A tunable impedance multiplier with high multiplication factor is described. A single externally connected resistor is used and the multiplier is free of passive elements. The circuit can realize a positive or a negative impedance multiplier. Applications of the design to low and high pass filters are also presented. The simulation and experimental results show that the new design enjoys a multiplication factor above 400 at 2 Hz-to 7 MHz.

A digitally controlled grounded capacitor multiplier includes: a single capacitor directly connected at one end to an input voltage and at another end to a negative input of an operational amplifier; the operational amplifier including a negative feedback loop; and a digitally controlled current amplifier (DCCA) connected to an output of the operational amplifier. The DCCA digitally controls the digitally controlled grounded capacitor multiplier. The digitally controlled grounded capacitor multiplier comprises only two active devices consisting of the operational amplifier and the DCCA.

A digitally controlled grounded capacitor multiplier includes: a single capacitor directly connected at one end to an input voltage and at another end to a negative input of an operational amplifier; the operational amplifier including a negative feedback loop; and a digitally controlled current amplifier (DCCA) connected to an output of the operational amplifier. The DCCA digitally controls the digitally controlled grounded capacitor multiplier. The digitally controlled grounded capacitor multiplier comprises only two active devices consisting of the operational amplifier and the DCCA.

A tunable impedance multiplier with high multiplication factor is described. A single externally connected resistor is used and the multiplier is free of passive elements. The circuit can realize a positive or a negative impedance multiplier. Applications of the design to low and high pass filters are also presented. The simulation and experimental results show that the new design enjoys a multiplication factor above 400 at 2 Hz-to 7 MHz.

A tunable impedance multiplier with high multiplication factor is described. A single externally connected resistor is used and the multiplier is free of passive elements. The circuit can realize a positive or a negative impedance multiplier. Applications of the design to low and high pass filters are also presented. The simulation and experimental results show that the new design enjoys a multiplication factor above 400 at 2 Hz-to 7 MHz.

A digitally controlled grounded capacitance multiplier circuit system and method is disclosed. The capacitance multiplier (CM) circuit comprises an op-amp, a digitally controlled current amplifier and two resistors in addition to a reference capacitor. The CM circuit is designed using complementary metal-oxide-semiconductor (CMOS) technology. The value of the equivalent capacitance can be adjusted through digitally programming the gain of the current amplifier. The CM circuit provides a significant multiplication factor while using two active devices.

An integrated circuit may include one or more circuits coupled to capacitance multiplier circuitry. The capacitance multiplier circuitry may include a capacitor, fixed and tunable resistances, and a transconductance circuit. The tunable resistance can be adjusted to control the overall capacitance of the capacitance multiplier circuitry. The transconductance circuit may include a transistor having a drain terminal coupled to a first electrical component and a source terminal coupled to a second electrical component. The first electrical component may be a diode-connected transistor, a direct shorting wire, a resistor, an inductor, or a current source. The second electrical component may be a current source, a direct shorting wire, a resistor, an inductor, or another diode-connected device. Configured in this way, the capacitance multiplier circuitry can provide a large adjustable amount of capacitance without a voltage drop and without consuming a large amount of power.