Provided is a relaxation oscillator having an extremely small temperature deviation in oscillation frequency. A first current (I1) generated by a reference voltage source and a first resistor having a positive first-order temperature coefficient is supplied to a first variable capacitor (C1) for oscillation, and a second current (I2) generated by a reference voltage source and a second resistor having a negative first-order temperature coefficient is supplied to a second variable capacitor (C2) for oscillation. A product of a value of a ratio of a first current to a second current and a value of a ratio of a first-order temperature coefficient of the second resistor to a first-order temperature coefficient of the first resistor, and a value of a ratio of a capacitance of the first variable capacitor to a capacitance of the second variable capacitor have the same absolute value and opposite signs.

Provided is a relaxation oscillator having an extremely small temperature deviation in oscillation frequency. A first current (I1) generated by a reference voltage source and a first resistor having a positive first-order temperature coefficient is supplied to a first variable capacitor (C1) for oscillation, and a second current (I2) generated by a reference voltage source and a second resistor having a negative first-order temperature coefficient is supplied to a second variable capacitor (C2) for oscillation. A product of a value of a ratio of a first current to a second current and a value of a ratio of a first-order temperature coefficient of the second resistor to a first-order temperature coefficient of the first resistor, and a value of a ratio of a capacitance of the first variable capacitor to a capacitance of the second variable capacitor have the same absolute value and opposite signs.

A comparator-based oscillator generates an output frequency that is relatively independent of comparator offset voltages. Charging/discharging circuitry controls the comparator input voltage, and logic circuitry generates the oscillator output (e.g., clock) signal and controls the charging/discharging circuitry. During an oscillator charging cycle, the charging/discharging circuitry drives the voltage at the comparator input node from a relatively low initial charging voltage level up to the comparator reference voltage. During an oscillator discharging cycle, the charging/discharging circuitry drives the voltage at the comparator input node from a relatively high initial discharging voltage level down to the comparator reference voltage. The initial charging and discharging voltage levels depend on the comparator reference voltage, such that a comparator offset voltage directly affects the initial charging and discharging voltage levels, thereby keeping the output frequency relatively unchanged.

An electronic circuit is configured to output an output signal after elapse of a predetermined time from a received trigger signal, and includes an oscillator configured to output a pulse signal having a predetermined oscillation frequency; a counter circuit configured to count the pulse signal from the oscillator upon receiving the trigger signal and to output the output signal in response to a count value reaching a predetermined value; and a trimming circuit including a plurality of trimming elements which includes a cuttable conductive part and configured to output a selection signal corresponding to a trimming element having a cut conductive part. In the trimming circuit, the trimming element, which corresponds to the oscillation frequency of the pulse signal output from the oscillator among the plurality of trimming elements, is cut, and the counter circuit is configured to set the predetermined value according to the selection signal.

An oscillator arrangement is provided, comprising a relaxation oscillator having an active state and an inactive state; a bias current circuit portion arranged to provide a bias current to the relaxation oscillator during said active state; and an electronic switch arranged to isolate said relaxation oscillator from the bias current circuit portion when in said inactive state. The oscillator arrangement is arranged to store an internal voltage value associated with said bias current and the bias current circuit portion is arranged to use the stored internal voltage value to generate the bias current when the oscillator is started up from the inactive state to the active state.

An oscillator arrangement is provided, comprising a relaxation oscillator having an active state and an inactive state; a bias current circuit portion arranged to provide a bias current to the relaxation oscillator during said active state; and an electronic switch arranged to isolate said relaxation oscillator from the bias current circuit portion when in said inactive state. The oscillator arrangement is arranged to store an internal voltage value associated with said bias current and the bias current circuit portion is arranged to use the stored internal voltage value to generate the bias current when the oscillator is started up from the inactive state to the active state.

An auto-tuned ramp generator and a method for generating a sawtooth signal are provided. In the method and apparatus, a sawtooth signal is compared to a first reference voltage and a second reference voltage. In response to determining that the sawtooth signal does not exceed the first reference voltage, the voltage level of the sawtooth signal is increased. In response to determining that the sawtooth signal exceeds the second reference voltage, the voltage level of the sawtooth signal is decreased. The voltage level the sawtooth signal is retained if the sawtooth signal remains between the first and second reference voltages.

An auto-tuned ramp generator and a method for generating a sawtooth signal are provided. In the method and apparatus, a sawtooth signal is compared to a first reference voltage and a second reference voltage. In response to determining that the sawtooth signal does not exceed the first reference voltage, the voltage level of the sawtooth signal is increased. In response to determining that the sawtooth signal exceeds the second reference voltage, the voltage level of the sawtooth signal is decreased. The voltage level the sawtooth signal is retained if the sawtooth signal remains between the first and second reference voltages.

A RC oscillator comprises a resistor unit. The resistor unit can comprise at least one set of compensation resistor. Each set of compensation resistor comprises a positive temperature coefficient resistor and a negative temperature coefficient resistor coupled in series with the positive temperature coefficient resistor.

A RC oscillator comprises a resistor unit. The resistor unit can comprise at least one set of compensation resistor. Each set of compensation resistor comprises a positive temperature coefficient resistor and a negative temperature coefficient resistor coupled in series with the positive temperature coefficient resistor.