A differential input stage of a circuit includes a first transistor, a second transistor, a third transistor, and a fourth transistor. Drains of the first and third transistors couple together at a first node, and drains of the second and fourth transistors couple together at a second node. A first slew boost circuit includes a fifth transistor and a first current mirror. A gate of the fifth transistor couples to the second node. A source of the fifth transistor couples to the first node. The first current mirror couples to the fifth transistor and to the second node. A second slew boost circuit includes a sixth transistor and a second current mirror. A gate of the sixth transistor couples to the first node. A source of the sixth transistor couples to the second node. The second current mirror couples to the sixth transistor and to the first node.

Each sub-stage of an amplifier stage includes a resistor coupled to another resistor in an adjacent sub-stage or to a high DC voltage, the resistor and the other resistor forming part of a string of equal valued resistors; an FET having a source coupled to a cathode of a Zener diode coupled in parallel with a capacitor, a drain coupled to another sub-stage in the string, an output node of the amplifier stage, or the high DC voltage; and at least one active device coupled to a gate of the FET and coupled to the resistor for providing high impedance between a voltage on a node of the resistor and the gate of the FET and a low impedance between the at least one active device and the gate of the FET, the at least one active device coupled to both the cathode and an anode of the Zener diode.

Disclosed herein are circuits, devices and methods that address challenges associated with power amplifier systems. A power amplifier system includes two or more fast error amplifiers coupled to corresponding power amplifiers. The fast error amplifiers are configured to generate envelope tracking signals based on a signal envelope, the envelope tracking signals modifying a DC-DC regulated voltage from a DC-DC converter to more efficiently operate the power amplifiers. By splitting the envelope tracking between two or more fast error amplifiers and amplification between corresponding two or more power amplifiers, the power, frequency or bandwidth, linearity, signal-to-noise ratio, efficiency, or the like of the power amplifier system can be improved. Wireless communications configurations with such power amplifier systems can provide uplink carrier aggregation and/or cellular signals based on standards and protocols that require increased bandwidth and/or power.

An operational amplifier circuit includes an operational amplifier and a control circuit. The operational amplifier includes a first input terminal, a second input terminal, and an output terminal connected with the second input terminal. The operational amplifier amplifies a signal provided through the first input terminal, and outputs the amplified signal through the output terminal. The control circuit generates switching signals. In response to the switching signals, the operational amplifier resets the output terminal to a preset voltage, charges the reset output terminal, and compares a voltage of the output terminal charged with a reference voltage provided through the first input terminal to output a comparison voltage.

The present invention relates to a multi-stage and feed forward compensated complimentary current field effect transistor amplifiers, enabling a charge-based approach that takes advantage of the exponential properties incurred in sub-threshold operation. A plurality of complimentary pairs of novel current field effect transistors are connected in series to form a multi-stage amplifier.

The present invention relates to a novel and inventive compound device structure for a low noise current amplifier or trans-impedance amplifier. The trans-impedance amplifier includes an amplifier portion, which converts current input into voltage using a complimentary pair of novel n-type and p-type current field-effect transistors (NiFET and PiFET) and a bias generation portion using another complimentary pair of NiFET and PiFET. Trans-impedance of NiFET and PiFET and its gain may be configured and programmed by a ratio of width (W) over length (L) of source channel over the width (W) over length (L) of drain channel (W/L of source channel/W/L of drain channel).

An amplification device comprising: a push pull circuit which amplifies an input signal; a diamond buffer circuit to which the signal which is amplified by the push pull circuit is input; and a current mirror circuit which is connected to a power supply and the diamond buffer circuit and is connected to a retraction current terminal of the push pull circuit.

An amplification circuit for RF power amplifiers is provided. The circuit includes two PMOS amplification modules and two NMOS amplification modules; each module includes a CSCG structure composed of a stack of K transistors. The first PMOS module and the first NMOS module are connected in series between a supply voltage and ground; gates of main amplification transistors of the first PMOS module and the first NMOS module are connected to a non-inverting input, and outputs of the first PMOS module and the first NMOS module are connected together to form an inverting output. The second PMOS module and the second NMOS module are similarly connected. Both the first and the second modules will be connected side-by-side as a pseudo differential structure to provide double push-pull function to the load. The present disclosure simultaneously achieves high power efficiency, and high linearity.

Disclosed is a circuit (100) for a medical device, comprising: a voltage converter (110, 300) which is configured to provide at least one supply potential (HV) depending on a control signal (302, PWM) provided to the voltage converter (110, 300), a control unit (P) which is configured to provide the control signal (302, PWM) for the voltage converter (110, 300), a signal source (TCA, 400) which is powered by the at least one supply potential (+HV) and which is configured to provide an output signal at an output of the signal source (TCA, 400), wherein the signal source (TCA, 400) is configured to provide the output signal dependent on an input signal (120) at an input of the signal source (TCA, 400), wherein the control unit (P) comprises: a prediction unit (160) which is configured to predict a change in the characteristic of the output signal based on at least one of a) at least one value of the input signal and b) at least one detected value of the output signal, and an adjusting unit (160) which is configured to adjust the control signal (302, PWM) based on the predicted change in the characteristic of the output signal.

A buffer amplifier circuit includes a buffer amplifier including a first differential amplifier having a first active load and a second differential amplifier having a second active load and a feedback circuit configured to feed an output signal of an output terminal of the buffer amplifier back to one of the first and second active loads using differential switch signals and an input signal of the buffer amplifier to enhance a slew rate of the output signal.