An RF tuner is described for handling RF signals in a broad frequency range and a broad power range while maintaining high linearity and tolerating high power blockers. A continuous feedback loop comprising a substantially linear LNA and an RF RSSI can adjust the power of the RF signal on the RF side. A substantially linear, variable gain transconductor may convert and amplify the voltage of the RF signal to a current signal. The converted signal may be down converted and filtered to an IF or baseband signal. An IF or baseband RSSI may measure the power of the down converted and filtered signal. The measured power may be compared against a preferred value to adjust the amplification of the transconductor.

An object of the disclosure is to provide a slope enhancement circuit, comprising an amplifier and a specific arrangement of capacitors and switches, further comprising a current digital to analog converter (IDAC), in a switched regulated current mirror. A method of sample and hold exploits the transient dynamics of the switched current mirror, to enhance the output current slope during PWM operation. A further object of the disclosure is to provide a low power, high speed switching type of regulated current mirror architecture. Still further, another object of the disclosure is to provide quick response to a sudden demand in current with a high degree of accuracy. Still further, another object of the disclosure is to provide a significant savings in circuit area.

An ultrasound circuit comprising a multi-stage trans-impedance amplifier (TIA) is described. The TIA is coupled to an ultrasonic transducer to amplify an electrical signal generated by the ultrasonic transducer in response to receiving an ultrasound signal. The TIA may include multiple stages, at least two of which operate with different supply voltages. The TIA may be followed by further processing circuitry configured to filter, amplify, and digitize the signal produced by the TIA.

An ultrasound circuit comprising a multi-stage trans-impedance amplifier (TIA) is described. The TIA is coupled to an ultrasonic transducer to amplify an electrical signal generated by the ultrasonic transducer in response to receiving an ultrasound signal. The TIA may include multiple stages, at least two of which operate with different supply voltages. The TIA may be followed by further processing circuitry configured to filter, amplify, and digitize the signal produced by the TIA.

An adaptive bias circuit for a power amplifier may include a terminal node coupled to the power amplifier. The adaptive bias circuit may also include a low impedance bias circuit coupled to the terminal node. The adaptive bias circuit may further include a high drive bias circuit coupled to the low impedance bias circuit through the terminal node. A separation device may be arranged between the low impedance bias circuit and the high drive bias circuit.

An adaptive bias circuit for a power amplifier may include a terminal node coupled to the power amplifier. The adaptive bias circuit may also include a low impedance bias circuit coupled to the terminal node. The adaptive bias circuit may further include a high drive bias circuit coupled to the low impedance bias circuit through the terminal node. A separation device may be arranged between the low impedance bias circuit and the high drive bias circuit.

A semiconductor integrated circuit includes a first pad provided on one end side of a first resistive element externally provided, a second pad provided on a different end side of the first resistive element, an operation amplifier, a first signal line wired between an output terminal of the operation amplifier and the first pad, a second signal line wired between one input terminal of the operation amplifier and the second pad, a first ESD (Electrostatic Discharge) protection element provided to the first signal line, and a third signal line, through which a voltage signal of the first pad is transmitted, the third signal line being connected to the first pad, and a second switch, which is selectively turned on, the second switch being provided on the third signal line.

A semiconductor integrated circuit includes a first pad provided on one end side of a first resistive element externally provided, a second pad provided on a different end side of the first resistive element, an operation amplifier, a first signal line wired between an output terminal of the operation amplifier and the first pad, a second signal line wired between one input terminal of the operation amplifier and the second pad, a first ESD (Electrostatic Discharge) protection element provided to the first signal line, and a third signal line, through which a voltage signal of the first pad is transmitted, the third signal line being connected to the first pad, and a second switch, which is selectively turned on, the second switch being provided on the third signal line.

A source follower includes a first transistor, a first output module, a second transistor, a second output module and a feedback module. The first terminal and the control terminal of the first transistor are configured to respectively receive a first base voltage and a first control voltage. The second terminal of the first transistor and the first output module are electrically connected to a first output terminal. The first terminal and the control terminal of the second transistor are configured to respectively receive a first base voltage and a second control voltage. The second terminal of the second transistor and the second output module are electrically connected to a second output terminal. The feedback module is electrically connected to the control terminal of the first transistor, the control terminal of the second transistor and a reference node of the second output module.

In accordance with an embodiment, a circuit includes an amplifier and a programmable capacitor coupled between an output of the first non-inverting and the input of the first amplifier.