An oscillator includes a first current source, a second current source, a first chopper circuit, a resistive component, a capacitive component, and a processing circuit. The first current source provides a first current. The second current source provides a second current. The first chopper circuit includes a first terminal coupled to the first current source, a second terminal coupled to the second current source, a third terminal coupled to the resistive component, and a fourth terminal coupled to the capacitive component. The processing circuit generates an output clock in response to a first voltage across the resistive component and a second voltage across the capacitive component. The first chopper circuit couples the first terminal and the second terminal to the third terminal and the fourth terminal, respectively and alternately. The resistive component and the capacitive component receive the first current and the second current, respectively and alternately.

Provided is a semiconductor integrated circuit including an oscillation circuit configured to output an oscillation signal, a heater configured to heat the oscillation circuit, a temperature sensor configured to detect a temperature of the oscillation circuit, and a nonvolatile memory configured to store temperature correction data. The oscillation circuit controls a frequency of the oscillation signal based on an output signal of the temperature sensor and the temperature correction data.

Provided is a semiconductor integrated circuit including an oscillation circuit configured to output an oscillation signal, a heater configured to heat the oscillation circuit, a temperature sensor configured to detect a temperature of the oscillation circuit, and a nonvolatile memory configured to store temperature correction data. The oscillation circuit controls a frequency of the oscillation signal based on an output signal of the temperature sensor and the temperature correction data.

A bandgap reference circuit includes a plurality of current sources including different temperature coefficients, a first trimmer, and a mixer. The first trimmer adjusts current amounts for a plurality of currents, which are individually output from each of the plurality of current sources, to be equal to each other. The mixer adjusts an aggregate ratio and combines the plurality of currents based on the aggregate ratio.

Provided is a relaxation oscillating circuit, which comprises a charging circuit, a discharging circuit, a switch circuit, a charging-discharging capacitor and an output circuit. The charging circuit comprises a first current source and a first isolating transistor. The discharging circuit comprises a second current source and a second isolating transistor. The switch circuit comprises a main charging transistor and an auxiliary charging transistor arranged as mirror and a main discharging transistor and an auxiliary discharging transistor arranged as mirror. The main charging transistor and the main discharging transistor are alternately conducted. According to a voltage of the charging-discharging capacitor, the output circuit outputs a clock signal and a control signal. The clock signal is connected to control ends of the auxiliary charging transistor and the auxiliary discharging transistor, and the control signal is connected to control ends of the main charging transistor and the main discharging transistor.

Provided is a relaxation oscillating circuit, which comprises a charging circuit, a discharging circuit, a switch circuit, a charging-discharging capacitor and an output circuit. The charging circuit comprises a first current source and a first isolating transistor. The discharging circuit comprises a second current source and a second isolating transistor. The switch circuit comprises a main charging transistor and an auxiliary charging transistor arranged as mirror and a main discharging transistor and an auxiliary discharging transistor arranged as mirror. The main charging transistor and the main discharging transistor are alternately conducted. According to a voltage of the charging-discharging capacitor, the output circuit outputs a clock signal and a control signal. The clock signal is connected to control ends of the auxiliary charging transistor and the auxiliary discharging transistor, and the control signal is connected to control ends of the main charging transistor and the main discharging transistor.

Embodiments of this application disclose an RC oscillator that amplifies a difference between a first voltage and a second voltage by using a first amplifier and a second amplifier. The first amplifier may include a first amplification circuit and a second amplification circuit. The first amplification circuit and the second amplification circuit may share a same voltage-current conversion circuit. The RC oscillator disclosed in the embodiments of this application not only avoids noise introduced by the first amplifier, but also reduces internal noise of the RC oscillator and a jitter of a clock signal.

A system may include a Class-D stage comprising a first high-side switch coupled between a supply voltage and a first output terminal of the Class-D stage, a second high-side switch coupled between the supply voltage and a second output terminal of the Class-D stage, a first low-side switch coupled between a ground voltage and the first output terminal, and a second low-side switch coupled between the ground voltage and the second output terminal. The system may also include current sensing circuitry comprising a sense resistor, such that an output current through a load coupled between the first output terminal and the second output terminal causes a first sense voltage proportional to the output current across the sense resistor. The system may additionally include a modulator for generating a differential pulse-width modulation driving signal to the first high-side switch, the second high-side switch, the first low-side switch, and the second low-side switch and pilot tone injection circuitry configured to inject a periodic pilot tone into the differential pulse-width modulation driving signal at a pilot tone frequency.

Disclosed are an on-chip RC oscillator, a chip, and a communication terminal. The on-chip RC oscillator comprises a stabilized voltage supply module, an RC core oscillator module, a frequency sampling and conversion module, and a frequency trimming module. By means of the frequency sampling and conversion module, the clock frequency of the oscillator is sampled and detected in real time, and the sampled clock frequency is converted into a voltage signal, and then analog-to-digital conversion is performed to obtain a corresponding digital code, so that when the clock frequency changes, the frequency trimming module circuit converts said digital code into a control signal; a voltage having a suitable temperature coefficient is outputted for the RC core oscillator; also, a zero temperature coefficient current of a suitable magnitude is outputted for the RC core oscillator module, so as to precisely calibrate the clock frequency.

Disclosed are an on-chip RC oscillator, a chip, and a communication terminal. The on-chip RC oscillator comprises a stabilized voltage supply module, an RC core oscillator module, a frequency sampling and conversion module, and a frequency trimming module. By means of the frequency sampling and conversion module, the clock frequency of the oscillator is sampled and detected in real time, and the sampled clock frequency is converted into a voltage signal, and then analog-to-digital conversion is performed to obtain a corresponding digital code, so that when the clock frequency changes, the frequency trimming module circuit converts said digital code into a control signal; a voltage having a suitable temperature coefficient is outputted for the RC core oscillator; also, a zero temperature coefficient current of a suitable magnitude is outputted for the RC core oscillator module, so as to precisely calibrate the clock frequency.