Nuvoton Technology Corporation

Ping-Wen Lai

Cheng-Tao Li

An oscillation circuit includes: a current mirror circuit outputting a reference current; a charging and discharging circuit charging a first charge storage element by using one of the reference currents or discharging the first charge storage element, to generate a first control voltage; an output stage circuit including a first switch transistor controlled by the first control voltage to output a first oscillation signal; a first resistor; a second resistor; and a diode circuit. The first resistor and the second resistor have same directional temperature drifts, a first resistance of the first resistor is greater than a second resistance of the second resistor, and a first resistance drift of the first resistor with a temperature variation is smaller than a second resistance drift of the second resistor with the temperature variation, such that the effect of the temperature variation on a frequency accuracy is reduced.

Oscillation circuit and circuit system using the same

A low power oscillator circuit with temperature compensation is illustrated. A current supply unit of an oscillator used to output an output current which is proportional to a reference current. As the temperature is increased, both a first threshold and the reference current of a unidirectional conduct in the temperature compensation circuit are decreased. Because a delay time of the oscillating signal is proportional to the first threshold voltage, and the delay time is inversely proportional to the reference current, the effects of the first threshold voltage and the reference current on the delay time are canceled, and the delay time of the oscillating signal is not affected by the temperature.

Low power oscillator circuit with temperature compensation circuit and electronic apparatus thereof

An oscillator equipped with a temperature compensation circuit is illustrated. Through the temperature compensation circuit, a transistor of a current mirror circuit of the oscillator which outputs a reference current to a voltage matching circuit is controlled by the temperature compensation voltage. Both of the temperature compensation voltage and a reference current decrease as the temperature rises, and a delay time of the oscillation voltage is proportional to the temperature compensation voltage and inversely proportional to the reference current. Therefore, the effects of temperature on the delay time just cancel each other out. The delay time of the oscillating voltage is related to the frequency of the clock signal. Therefore, if the delay time of the oscillating voltage is not affected by temperature, the frequency of the clock signal will not be affected by temperature.

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Zhubei, Taiwan

Ping-Wen Lai