Richwave Technology Corp.

Shun-Nan Tai

Che-Sheng Chen

Yao Hui Chiang

A radio frequency (RF) amplifier and a bias circuit are provided. The RF amplifier includes an amplifier, a first inductive-capacitive resonance circuit, and a first bias circuit. The amplifier includes an input terminal configured to receive an incoming RF signal through a first RF path. The first inductive-capacitive resonance circuit includes a first terminal coupled to a first reference voltage. A second terminal of the first inductive-capacitive resonance circuit is coupled to the first RF path. In response to the first reference voltage being at a first reference level, the RF amplifier is enabled; in response to the first reference voltage being at a second reference level, the RF amplifier is disabled. The first bias circuit includes a first terminal configured to be coupled to the first reference voltage and a second terminal coupled to the input terminal of the amplifier to provide a first direct current (DC) component.

Radio frequency amplifier and bias circuit

A power detector includes a detection circuit and a bias circuit. The detection circuit is used to receive an input signal and output a power indication signal. The bias circuit includes a first impedance unit, a second impedance unit and a transistor. The transistor includes a first terminal and a control terminal coupled to the first impedance unit, and a second terminal. The second impedance unit is coupled between the first terminal of the transistor and an output terminal of the bias circuit, or between the second terminal of the transistor and a second terminal of the bias circuit. The output terminal of the bias circuit is coupled to an input terminal of the detection circuit, and is used to output a bias signal.

Power detector

A voltage regulator is provided. The voltage regulator includes an output terminal, a transistor, a primary driving circuit, and a secondary driving circuit. The output terminal is adapted to output an output voltage. The primary driving circuit is coupled to a control terminal of the transistor. The secondary driving circuit is coupled between the control terminal of the transistor and a predetermined voltage terminal. When the voltage regulator operates in a start-up mode, the transistor is driven by the primary driving circuit and the secondary driving circuit, and the control terminal of the transistor and the predetermined voltage terminal are electrically coupled by the secondary driving circuit. When the voltage regulator operates in a normal mode, the transistor is driven by the primary driving circuit, and an electrical coupling between the control terminal of the transistor and the predetermined voltage terminal is disconnected by the secondary driving circuit.

Voltage regulator has a characteristic of fast activation

A bandgap voltage reference circuit configured to generate a bandgap reference voltage is provided. The bandgap voltage reference circuit includes a bandgap current generating circuit, a differential pair circuit and a flipped voltage follower. The bandgap current generating circuit converts the bandgap reference voltage into a bandgap current and generates a first voltage and a second voltage according to the bandgap current. The differential pair circuit is coupled to the bandgap current generating circuit to receive the first voltage and the second voltage and configured to reduce a voltage difference between the first voltage and the second voltage and generate a third voltage. The flipped voltage follower is coupled to the differential pair circuit to receive the third voltage and generates the bandgap reference voltage accordingly.

Bandgap voltage reference circuit

A boost circuit for use in a power amplifier includes a voltage-to-voltage generator, a voltage-to-current converter, and a differential current generator. The voltage-to-voltage generator is configured to generate a converting voltage according to a reference voltage, wherein the absolute value of the slope at the rising edge of the converting voltage is smaller than the absolute value of the slope at the rising edge of the reference voltage. The voltage-to-current converter is configured to generate first current according to the converting voltage, wherein the waveform of the first current corresponds to the waveform of the converting voltage. The differential current generator is configured to generator second current associated with the waveform of the reference voltage, thereby outputting operational current whose value is associated with the first current and the second current.

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Taipei, Taiwan

Shun-Nan Tai