Seiko Epson Corporation

Kohei Beppu

Takehiro Yamamoto

A circuit device includes a waveform-shaping circuit that waveform-shapes an oscillation signal and provides an output clock signal based on a clock signal. A bias voltage output circuit of the circuit device provides a bias voltage of the oscillation signal that is input to the waveform-shaping circuit. A comparator of the circuit device compares a DC voltage obtained by smoothing the clock signal with a reference voltage. A logic circuit of the circuit device sets an adjustment value of the bias voltage. In a test mode of the logic circuit, the logic circuit changes the adjustment value to determine a set value of the adjustment value based on output of the comparator when the adjustment value is changed and stores the determined set value in a storage circuit.

Circuit device, oscillator, and manufacturing method

A circuit apparatus includes an oscillation circuit that generates an oscillation signal, a first buffer circuit that outputs a first clock signal based on the oscillation signal, a second buffer circuit that outputs a second clock signal based on the first clock signal, a first terminal electrically couplable to a first node via which the first buffer circuit outputs the first clock signal, and a second terminal electrically coupled to a second node via which the second buffer circuit outputs the second clock signal, and the rise period of the first clock signal is shorter than the rise period of the second clock signal.

Circuit apparatus and oscillator

The circuit device includes a first MOS transistor of a first conductivity type a source of which is coupled to a first power supply voltage node, a second MOS transistor of a second conductivity type a source of which is coupled to a second power supply voltage node, a first variable resistance circuit which is coupled between a drain of the first MOS transistor and an output node, and which includes a first switch, and a second switch coupled between the drain of the first MOS transistor and the second power supply voltage node. The control circuit performs control of making the first switch OFF and making the second switch ON when the clock signal fails to be output from the output node, and making the first switch ON and making the second switch OFF when the clock signal is output from the output node.

Growing community of inventors

Minowa, Japan

Kohei Beppu