The disclosure discloses an RC oscillating circuit. A first end of a capacitor is grounded, a second end of the capacitor is connected to a charging path, a discharging path and a comparator, A first input end of a comparator is connected to first reference voltage. An output end of the comparator outputs a first output signal and is connected to a control end of the discharging path. The first reference voltage provides the flipped voltage of the comparator The first output signal forms an output clock signal. A first regulating circuit is configured to regulate the magnitude of the charging current and realize coarse frequency tuning. A second regulating circuit is configured to regulate the magnitude of the first reference voltage and realize fine frequency tuning. The disclosure has the advantages of low power consumption, fast start, high precision and wide tuning range.

The disclosure discloses an RC oscillating circuit. A first end of a capacitor is grounded, a second end of the capacitor is connected to a charging path, a discharging path and a comparator, A first input end of a comparator is connected to first reference voltage. An output end of the comparator outputs a first output signal and is connected to a control end of the discharging path. The first reference voltage provides the flipped voltage of the comparator The first output signal forms an output clock signal. A first regulating circuit is configured to regulate the magnitude of the charging current and realize coarse frequency tuning. A second regulating circuit is configured to regulate the magnitude of the first reference voltage and realize fine frequency tuning. The disclosure has the advantages of low power consumption, fast start, high precision and wide tuning range.

A ramp generator includes an operational amplifier having an output to generate a ramp signal. An integration current source is coupled to a first input and a reference voltage is coupled to a second input of the operational amplifier. A feedback capacitor and a reset switch are coupled between the first input and the output of the operational amplifier. The reset switch is turned on to reset the ramp generator. A ramp event is configured to be generated in the ramp signal at the output of the operational amplifier in response to the reset switch being turned off. An assist current source is coupled between the output of the operational amplifier and ground. The assist current source is configured to conduct an assist current from the output of the operational amplifier to ground in response to the reset switch being turned off.

A ramp generator includes an operational amplifier having an output to generate a ramp signal. An integration current source is coupled to a first input and a reference voltage is coupled to a second input of the operational amplifier. A feedback capacitor and a reset switch are coupled between the first input and the output of the operational amplifier. The reset switch is turned on to reset the ramp generator. A ramp event is configured to be generated in the ramp signal at the output of the operational amplifier in response to the reset switch being turned off. An assist current source is coupled between the output of the operational amplifier and ground. The assist current source is configured to conduct an assist current from the output of the operational amplifier to ground in response to the reset switch being turned off.

A relaxation oscillator includes an adjustable reference circuit generator to produce a reference current which is applied to a charging circuit. The charging circuit is configured to charge a capacitive node as a function of the reference current and a capacitance of an adjustable capacitor that is operably coupled to the capacitive node. A comparator having inputs operatively coupled to a reference voltage node and to the capacitive node, generates a comparator output. A control circuit alternatively enables the charging circuit to charge the capacitive node and to discharge the capacitive node in response to changes in the comparator output. Also, the control circuit outputs and oscillator output signal have an oscillator period as a function of the adjustable capacitance and the adjustable reference current.

A relaxation oscillator includes an adjustable reference circuit generator to produce a reference current which is applied to a charging circuit. The charging circuit is configured to charge a capacitive node as a function of the reference current and a capacitance of an adjustable capacitor that is operably coupled to the capacitive node. A comparator having inputs operatively coupled to a reference voltage node and to the capacitive node, generates a comparator output. A control circuit alternatively enables the charging circuit to charge the capacitive node and to discharge the capacitive node in response to changes in the comparator output. Also, the control circuit outputs and oscillator output signal have an oscillator period as a function of the adjustable capacitance and the adjustable reference current.

An oscillator circuit includes a first comparator that outputs a first signal indicative of a comparison result between an input potential and a threshold, a second comparator that outputs a second signal indicative of a comparison result between an input potential and the threshold, a RS flip-flop circuit that receives the first signal and the second signal and outputs first and second oscillation signals, a first charge/discharge unit that charges and discharges a first capacitor based on the first oscillation signal, a second charge/discharge unit that charges and discharges a second capacitor based on the second oscillation signal, a first dummy switch controlled to be on and off according to the second oscillation signal and adding a predetermined capacity to a first node, and a second dummy switch controlled to be on and off according to the first oscillation signal and adding a predetermined capacity to a second node.

An oscillator circuit includes a first comparator that outputs a first signal indicative of a comparison result between an input potential and a threshold, a second comparator that outputs a second signal indicative of a comparison result between an input potential and the threshold, a RS flip-flop circuit that receives the first signal and the second signal and outputs first and second oscillation signals, a first charge/discharge unit that charges and discharges a first capacitor based on the first oscillation signal, a second charge/discharge unit that charges and discharges a second capacitor based on the second oscillation signal, a first dummy switch controlled to be on and off according to the second oscillation signal and adding a predetermined capacity to a first node, and a second dummy switch controlled to be on and off according to the first oscillation signal and adding a predetermined capacity to a second node.

An oscillator circuit includes an initial level setting circuit configured to operate in an on-state during an initial operation of the oscillator circuit to supply a first level voltage to a first node and a second level voltage to a second node, a switching circuit configured to connect a power supply voltage terminal and a ground terminal to the first or second node in response to first and second clock signals having different phases after the initial operation, a signal generation circuit connected between the first and second nodes and configured to perform charging and discharging operations based on a potential difference between the first and second nodes, and generate first and second voltages determined by the charging and discharging operations, and an inverter circuit configured to generate the first clock signal based on the first voltage, and generate the second clock signal based on the second voltage.

An oscillator circuit includes an initial level setting circuit configured to operate in an on-state during an initial operation of the oscillator circuit to supply a first level voltage to a first node and a second level voltage to a second node, a switching circuit configured to connect a power supply voltage terminal and a ground terminal to the first or second node in response to first and second clock signals having different phases after the initial operation, a signal generation circuit connected between the first and second nodes and configured to perform charging and discharging operations based on a potential difference between the first and second nodes, and generate first and second voltages determined by the charging and discharging operations, and an inverter circuit configured to generate the first clock signal based on the first voltage, and generate the second clock signal based on the second voltage.