A class AB buffer includes an output stage and an input stage. The output stage includes a first output transistor and a second output transistor. The second output transistor is coupled to the first output transistor. The input stage is coupled to the output stage. The input stage includes a first cascode transistor, a first switch, a second cascode transistor, and a second switch. The first switch is coupled to the first cascode transistor and the first output transistor. The second switch is coupled to the first switch, the second cascode transistor, and the first output transistor.

Systems, methods and apparatus for practical realization of an integrated circuit comprising a stack of transistors operating as an RF amplifier are described. As stack height is increased, capacitance values of gate capacitors used to provide a desired distribution of an RF voltage at the output of the amplifier across the stack may decrease to values approaching parasitic/stray capacitance values present in the integrated circuit which may render the practical realization of the integrated circuit difficult. Coupling of an RF gate voltage at the gate of one transistor of the stack to a gate of a different transistor of the stack can allow for an increase in the capacitance value of the gate capacitor of the different transistor for obtaining an RF voltage at the gate of the different transistor according to the desired distribution.

A local oscillator buffer circuit comprises a complementary common-source stage comprising a first p-channel transistor (MCSP) and a first n-channel transistor (MCSN), arranged such that their respective gate terminals are connected together at a first input node, and their respective drain terminals of each of is connected together at a buffer output node. A complementary source-follower stage comprises a second p-channel transistor (MSFP) and a second n-channel transistor (MSFN), arranged such that their respective gate terminals are connected together at a second input node, and their respective source terminals are connected together at the buffer output node.

This disclosure relates to an output buffer including an input stage configured to monitor a difference between an input voltage and an output voltage, a current summing stage configured to generate amplified currents and control voltages according to the difference between the input voltage and the output voltage monitored by the input stage, an output stage configured to perform a pull-up operation or a pull-down operation according to the control voltages output from the current summing stage to generate the output voltage at an output terminal, and a slew boost circuit configured to perform a slew boost operation of adjusting some currents among currents provided from the current summing stage to the input stage according to the difference between the input voltage and the output voltage by monitoring the difference between the input voltage and the output voltage and selectively perform the slew boost operation by monitoring the control voltages.

A receiver topology for supporting various combinations of interband carrier aggregation (CA) signals, intraband non-contiguous CA and non-CA signals having different combinations of signals aggregated therein.

Apparatus and methods for reconfigurable power amplifiers are disclosed. In certain embodiments, a mobile device includes a transceiver configured to generate a first radio frequency signal of a first frequency band and a second radio frequency signal of a second frequency band, and a front-end system including a push-pull power amplifier configured to selectively amplify one of the first radio frequency signal or the second radio frequency signal based on a band control signal. The push-pull power amplifier includes an input balun, an output balun, and a pair of amplifiers coupled between the input balun and the output balun. The band control signal is operable to control an input capacitance of the pair of amplifiers.

The invention relates to a method for controlling a driver circuit. The method comprises operating an amplifier for providing an output signal, for example an electronic signal for driving or controlling a load, for example a voltage or a current, based on a control signal. The method further comprises operating a comparator for providing the control signal by comparing an input signal, for example an electronic signal with a lower level or a lower amplitude than the output signal, to a feedback signal, wherein the feedback signal is based on the output signal. The method further comprises providing a first supply voltage to the comparator, and providing a second supply voltage to the amplifier, wherein the second supply voltage is higher than the first supply voltage.

Described examples include Ethernet physical layer (PHY) interface integrated circuits with transmit interface circuitry for transmitting data to an Ethernet network through a magnetic interface, which includes a voltage mode first amplifier with an output that generates a first voltage signal from a supply voltage according to a data input signal. The transmit interface circuit also includes a feedforward second amplifier circuit with an output stage that operates in a first mode to generate a current signal from the supply voltage according to the first voltage signal and to provide the current signal to the first amplifier output to boost a peak voltage at the output above the supply voltage to facilitate support for higher peak signal voltage swings for 10Base-T applications while using 2.5 volt or other low voltage supply levels.

Described examples include Ethernet physical layer (PHY) interface integrated circuits with transmit interface circuitry for transmitting data to an Ethernet network through a magnetic interface, which includes a voltage mode first amplifier with an output that generates a first voltage signal from a supply voltage according to a data input signal. The transmit interface circuit also includes a feedforward second amplifier circuit with an output stage that operates in a first mode to generate a current signal from the supply voltage according to the first voltage signal and to provide the current signal to the first amplifier output to boost a peak voltage at the output above the supply voltage to facilitate support for higher peak signal voltage swings for 10Base-T applications while using 2.5 volt or other low voltage supply levels.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier includes a PMOSFET and an NMOSFET. The PMOSFET has a gate electrode serving as a first input end and a drain coupled to an output end. The NMOSFET has a gate electrode serving as a second input end and a drain coupled to the output end. The output amplifier outputs an output voltage at the output end, and is coupled to the input amplifier via at least one of the first and second input ends. The diode device is coupled between the output end and the at least one of the first and second input ends of the output amplifier. When a voltage difference between the output end and the at least one of the first and second input ends of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.