A circuit comprising: an input terminal; a first amplifier coupled to the input terminal of the circuit to receive an input signal; a first inductor having a first terminal coupled to the input terminal and a second terminal configured to be coupled to the ground terminal, wherein the first inductor is arranged with a second inductor and configured to magnetically couple therewith, wherein said second inductor is coupled to the first amplifier and is configured to sense a current through the amplifier.

Existing proportional to absolute temperature (PTAT)/complementary-to-absolute-temperature (CTAT) reference voltage circuit requires a large components count and foot print, precise device matching for accuracy and unsatisfactory sensitivity error or variation to temperature and humidity. The present invention relates to a novel approach for such reference voltage circuit based on a self-biased complementary pair of n-type and p-type current field-effect transistors, which provides rail PTAT, rail CTAT and analog reference voltages.

The present invention relates to an improvement to a current field effect transistor and trans-impedance MOS devices based on a novel and inventive compound device structure, enabling a charge-based approach that takes advantage of sub-threshold operation, for designing analog CMOS circuits. The present invention further relates to a super-saturation current field effect transistor (xiFET), having a source, a drain, a diffusion, a first gate, and a second gate terminals, in which a source channel is defined between the source and diffusion terminals, a drain channel is defined between the drain and diffusion terminals. The first gate terminal is capacitively coupled to the source channel; and the second gate terminal is capacitively coupled to said drain channel. The diffusion terminal receives a current causing change in diffused charge density throughout said source and drain channel. The xiFET provides a fundamental building block for designing various analog circuits.

Existing proportional to absolute temperature (PTAT)/complementary-to-absolute-temperature (CTAT) reference voltage circuit requires a large components count and foot print, precise device matching for accuracy and unsatisfactory sensitivity error or variation to temperature and humidity. The present invention relates to a novel approach for such reference voltage circuit based on a self-biased complementary pair of n-type and p-type current field-effect transistors, which provides rail PTAT, rail CTAT and analog reference voltages.

The present invention relates to an improvement to a current field effect transistor and trans-impedance MOS devices based on a novel and inventive compound device structure, enabling a charge-based approach that takes advantage of sub-threshold operation, for designing analog CMOS circuits. The present invention further relates to a super-saturation current field effect transistor (xiFET), having a source, a drain, a diffusion, a first gate, and a second gate terminals, in which a source channel is defined between the source and diffusion terminals, a drain channel is defined between the drain and diffusion terminals. The first gate terminal is capacitively coupled to the source channel; and the second gate terminal is capacitively coupled to said drain channel. The diffusion terminal receives a current causing change in diffused charge density throughout said source and drain channel. The xiFET provides a fundamental building block for designing various analog circuites.

An operational amplifier includes an input stage configured to receive a first input voltage and a second input voltage and a slew boost circuit coupled to the input stage and configured to selectively increase current through the input stage. The operational amplifier also includes an output stage coupled to the input stage and configured to generate an output voltage, and a slew boost disable circuit configured to assert a control signal to the slew boost circuit to disable the slew boost circuit. The slew boost circuit is disabled when both: the first input voltage being more than a first threshold voltage different from the second input voltage and the output voltage failing to change by more than a second threshold rate.

The present invention relates to an improvement to a current field effect transistor and trans-impedance MOS devices based on a novel and inventive compound device structure, enabling a charge-based approach that takes advantage of sub-threshold operation, for designing analog CMOS circuits. The present invention further relates to a super-saturation current field effect transistor (xiFET), having a source, a drain, a diffusion, a first gate, and a second gate terminals, in which a source channel is defined between the source and diffusion terminals, a drain channel is defined between the drain and diffusion terminals. The first gate terminal is capacitively coupled to the source channel; and the second gate terminal is capacitively coupled to said drain channel.The diffusion terminal receives a current causing change in diffused charge density throughout said source and drain channel. The xiFET provides a fundamental building block for designing various analog circuites.

An input stage of an operational amplifier receives first and second input voltages. An output slew detection circuit decreases a first current responsive to slewing of an output of the operational amplifier and increases the first current responsive to no slewing. A slew boost and differential input voltage detection generates a second current at a first level when the first and second input voltages are approximately equal and to generate the second current at a second level, smaller than the first level, responsive to the first and second input voltages not being approximately equal. A voltage on a capacitor increases responsive to the first current from the output slew detection circuit increasing and responsive to the second current being at the second level. A current mirror is activated responsive to the voltage on the capacitor exceeding a second threshold. The current mirror decreases a third current of the input stage.

An operational amplifier includes an input stage configured to receive a first input voltage and a second input voltage and a slew boost circuit coupled to the input stage and configured to selectively increase current through the input stage. The operational amplifier also includes an output stage coupled to the input stage and configured to generate an output voltage, and a slew boost disable circuit configured to assert a control signal to the slew boost circuit to disable the slew boost circuit. The slew boost circuit is disabled when both: the first input voltage being more than a first threshold voltage different from the second input voltage and the output voltage failing to change by more than a second threshold rate.

An input stage of an operational amplifier receives first and second input voltages. An output slew detection circuit decreases a first current responsive to slewing of an output of the operational amplifier and increases the first current responsive to no slewing. A slew boost and differential input voltage detection generates a second current at a first level when the first and second input voltages are approximately equal and to generate the second current at a second level, smaller than the first level, responsive to the first and second input voltages not being approximately equal. A voltage on a capacitor increases responsive to the first current from the output slew detection circuit increasing and responsive to the second current being at the second level. A current mirror is activated responsive to the voltage on the capacitor exceeding a second threshold. The current mirror decreases a third current of the input stage.