Seiko Instruments Inc

Sii Semiconductor Corporation

Ablic Inc.

Hiroyuki Masuko

Michiyasu Deguchi

Fumiyasu Utsunomiya

Kosuke Takada

Hisashi Hasegawa

Yutaka Sato

Takayuki Takashina

Kiyoshi Yoshikawa

Toshiyuki Tsuzaki

Masayuki Hashitani

Osamu Uehara

Hiroki Wake

To provide a constant current charging device capable of shortening a total charging time of a secondary battery even if an internal impedance of the secondary battery becomes high. A constant current charging device is provided which is equipped with a charging completion voltage detector, a battery voltage drop detector, an up-down counter which adds data when the up-down counter receives a detection signal of the charging completion voltage detector, subtracts the data when the up-down counter receives a detection signal of the battery voltage drop detector, and outputs the subtracted data, and a constant current generating circuit which switches a charging current to a secondary battery according to the data outputted from the up-down counter.

Constant current charging device

To provide a DC-DC converter which prevents overshoot from occurring in an output voltage even when a power supply voltage rises from a voltage lower than a desired output voltage of the DC-DC converter to a normal voltage. A DC-DC converter is equipped with a 100% DUTY detection circuit which detects a 100% DUTY state of a PWM comparator, a power supply voltage rise detection circuit which detects a rise in a power supply voltage, and a discharge control circuit which lowers an output voltage of an error amplifier. The DC-DC converter is configured to lower the output voltage of the error amplifier when a power supply voltage rise detection signal is outputted where a 100% DUTY state is reached and the output voltage of the error amplifier is higher than a predetermined voltage.

DC-DC converter

In the semiconductor device including the off transistor serving as an ESD protection element and an output element between a first external connection terminal and a second external connection terminal connected to a VSS, a seal ring wire is connected in parallel, by a connection wire, to a first internal wire extending from the second external connection terminal to the source of the off transistor, and a parasitic resistance of the first internal wire is smaller than a parasitic resistance of a second internal wire connecting the source of the off transistor and a source of the output element to each other.

Semiconductor device

A switching regulator is provided which can prevent overshooting in an output voltage even when a source voltage is returned to a normal voltage from a voltage lower than a desired output voltage of the switching regulator. The switching regulator includes a 100% duty detector circuit that detects that a PWM comparator is in a 100%-duty state and a discharge accelerator circuit that detects that the output of an error amplifier discharges the voltage of a phase compensating capacitor and that accelerates the discharge, and activates the discharge accelerator circuit when the 100% duty detector circuit detects the 100%-duty state.

Switching regulator and electronic apparatus

Provided is a power supply switching circuit capable of efficiently supplying a desired voltage among a plurality of voltages to a load. In the case of a P-type semiconductor substrate, N-type MOS transistors are provided between a load and an AC adapter and between the load and a battery, and hence no parasitic diode exists between the load and the AC adapter or the battery, resulting in no current path due to the parasitic diode. Thus, when the AC adapter and the battery are connected to the power supply switching circuit, the N-type MOS transistor is turned off, whereby the current path between the battery and the load is cut off completely and the N-type MOS transistor is turned on. Accordingly, the battery cannot supply a voltage to the load while only the AC adapter can supply a voltage to the load.

Power supply switching circuit

A semiconductor device has power supply pads including a first power supply pad and at least one second power supply pad that are connected to internal power supply wirings through an internal circuit so that the first and second power supply pads are set to the same potential. The first power supply pad is bonded by a wire to a lead to which a supply voltage is applied and is connected to the round power supply wiring through a round power supply connection wiring. A signal pad from which electrostatic noise enters into the semiconductor device is provided. An input protection circuit is connected between the signal pad and the internal circuit and is connected to the round power supply wiring through a protection circuit power supply wiring. The second power supply pad is not bonded by a wire to a lead to which a supply voltage is applied and is not connected to the round power supply wiring so that when electrostatic noise enters the signal pad, the electrostatic noise is discharged to the exterior of the semiconductor device without the electrostatic noise being led to the internal circuit.

Semiconductor device and method of manufacturing the same

Provided is an electronic device including a charge pump circuit whose circuit structure is simple and boosting efficiency is high. The charge pump circuit uses MOSFETs as charge transfer elements and has a structure in which a voltage of a gate of a charge transfer MOSFET is controlled to a predetermined level based on a dividing voltage caused by a first resistor connected between a source and the gate thereof and a second resistor connected between a drain and the gate thereof and a clock pulse for on/off control of the charge transfer MOSFET is supplied to the gate through a capacitor.

Growing community of inventors

Chiba, Japan

Hiroyuki Masuko