Seiko Instruments Inc

Ablic Inc.

Sii Semiconductor Corporation

Fumimasa Azuma

Yoshiomi Shiina

Daiki Endo

Takashi Matsuda

An input circuit includes a first input transistor and a second input transistor connected to an input terminal; a current source which makes a current flow in the second input transistor through a current mirror; a switch provided between the current mirror and the current source, and having a switch control terminal connected to the drain of the first input transistor; and a transistor connected to the first input transistor, on/off of the transistor being controlled by an output signal, wherein a current drivability of the second input transistor is switched by an output signal, and a threshold voltage to the input signal is determined based on the current drivability of the second input transistor and the current source.

Input circuit having hysteresis without power supply voltage dependence

To provide an overheat protection circuit which is not affected by a leak current while being low in current consumption and good in detection accuracy, and a voltage regulator equipped with the overheat protection circuit. An overheat protection circuit is configured to include a leak current detection circuit which detects that a leak current has flowed at a high temperature, a bias circuit which allows a bias current to flow in response to an output signal of the leak current detection circuit, and a temperature detection circuit operated by the bias current.

Overheat protection circuit and voltage regulator

Provided is a voltage regulator including an overcurrent protection circuit in which an output voltage-output current characteristic exhibits an optimal fold-back characteristic even when an overcurrent state is detected. The overcurrent protection circuit includes a control circuit for generating a current in accordance with an output voltage, and controls a gate of an output transistor with use of a current obtained by subtracting the current from a sense current flowing in accordance with an output current.

Voltage regulator

Provided is a voltage regulator capable of suppressing an overshoot with low current consumption. A comparator of an overshoot detection circuit is activated only when a power supply fluctuation occurs, and the comparator outputs a signal for reducing an overshoot occurring in an output voltage. In a steady state, the comparator of the overshoot detection circuit is turned off to prevent the current from being consumed.

Growing community of inventors

Phnom Penh, Cambodia

Fumimasa Azuma