Hitachi, Ltd.

Renesas Technology Corp.

Other

Hitachi Ulsi Systems Co., Ltd.

Hitachi Microcomputer Engineering, Ltd.

Hitachi Hybrid Network Co., Ltd.

Microcomputer System Ltd.

Norihisa Yamamoto

Kazuki Watanabe

Kazuhiro Matsushita

Ryouzou Yoshino

Hisataka Tsunoda

Hajime Kinota

Keiji Kamei

Hideo Nishijima

Takashi Kurihara

Isao Fukushima

Yasunori Kobori

Makoto Furihata

Yoshinori Masuda

Yutaka Nakadai

Hirokazu Kitamura

Toshiaki Shibata

Tadashi Matsushima

Shikiko Nachi

Fumihiro Takahashi

Yuki Matsuda

Yasuyoshi Nakajima

Katsuyoshi Yamashige

In an IC card in which an internal circuit is operated by an internal power supply formed from alternate current from outside received by an antenna, the voltage of the internal power supply sometimes changes due to the operation of the internal circuit. Therefore, the voltage controlling circuit of the present invention includes a voltage controlling current source, and when the internal circuit is not operated and the current higher than a predetermined current is detected in the voltage controlling current source, an operating current detector circuit outputs an enable signal. When the internal circuit is operated in response to the enable signal, the current consumed in the internal circuit is subtracted from the current passing through the voltage controlling current source. Consequently, the current change in the entire internal power supply can be prevented, and the output voltage of the internal power supply can be kept constant.

Semiconductor device and IC card

A semiconductor integrated circuit includes a demodulating circuit, a plurality of sampling circuits each capable of sampling output signals of the demodulating circuit, a plurality of detection circuits capable of detecting headers of output signals of the sampling circuits, a plurality of processing circuits capable of performing a predetermined data process based on the detection results of the detection circuits, and a circuit capable of determining a match to a preset communication method from results of the header detection by the detection circuits. By performing processes adapted to different communication methods in parallel, time required to establish a connection and enable information to be transmitted/received is reduced.

Semiconductor integrated circuit device and noncontact IC card

In a semiconductor integrated circuit device and a contactless electronic device, an AC voltage is applied to first and second input terminals. A rectification transistor having a drain (or collector) connected to a second input terminal and gate (or base) and drain (or collector) connected to each other through a first resistor supplies a rectified current between the first and second input terminals. A first voltage detector means produces a control voltage so that the rectified voltage obtained on the source (or emitter) side of the first rectification transistor is equal to a predetermined reference voltage. The first voltage controlled current source can produce current in accordance with the control voltage and supply the current to the first resistor. Such a power supply circuit is mounted in the contactless electronic device.

Semiconductor integrated circuit device and contactless electronic device

A nonvolatile memory device and a data processing system with a reduced layout area are capable of efficiently generating a high voltage without deteriorating the charge transfer efficiency of a charge pump circuit. The charge pump circuit in a nonvolatile memory device includes a plurality of stages of charge pump unit circuits. A voltage generating unit provides, as a control signal to the gate of a first MOS transistor for transferring charges from a first capacitor of a charge pump unit circuit of one stage to a first capacitor at the next stage, a fourth signal having an amplitude of a difference voltage between the power supply voltage and the charge pump voltage of the first capacitor at the one stage. The fourth control signal is obtained from second and third signals each changing in amplitude of the power supply voltage. The second signal is supplied via a second capacitor.

Generating high voltages in nonvolatile memory devices and data processing systems

A semiconductor integrated circuit device and a contactless electronic device are provided with a power supply circuit producing a stable smooth voltage with high efficiency for stable operation of an inner circuit. An AC voltage is applied to first and second input terminals and a rectification transistor having drain (or collector) connected to second input terminal and gate (or base) and drain (or collector) connected to each other through resistor supplies a rectified current between the first and second input terminals. The first voltage detection means produces control voltage so that the rectified voltage obtained on the source (or emitter) side of the first rectification transistor is equal to the predetermined reference voltage. The first voltage controlled current source can produce current in accordance with the control voltage and supply the current to the first resistor means. Such power supply circuit is mounted in the contactless electronic device.

Phase locked loop circuit and a picture reproducing device

In a video signal apparatus, a carrier signal generating circuit includes a VCO for generating a signal having a frequency at least twice that of a carrier signal necessary for conversion to a lower band with a sub-carrier in an NTSC system, a one-half divider circuit for dividing the VCO frequency signal by two, a delayed flip-flop circuit for receiving the divided signal and the sub-carrier signal to generate a difference frequency signal, a 1/40 divider circuit for dividing the Q output, a phase comparator circuit for comparing the phases of the 1/40 divided signal and the horizontal synchronizing signal to output a phase difference, a frequency discriminator circuit for comparing the phase of the flip-flop output with the frequency-divided output of the horizontal synchronizing signal to output a frequency error, and a circuit for converting the output of the phase comparator circuit and the frequency error into DC voltages and applying their sum as a control voltage for the VCO. A CR constant control circuit controls the CR constant of a four-phase signal generator for converting the output of the one-half divider circuit into a four-phase signal.

Carrier signal generating circuit in video signal recording/reproducing

A frequency-voltage converter comprising a feedback frequency generating means associated with controlled means, a saw-tooth wave generating means, a current source for the saw-tooth wave, pulse generating means and sample-and-hold means, the frequency-voltage converter being characterized by further provision of supply voltage switching means for changing the feedback frequency of the controlled means by changing the voltage to be supplied to the current source to change the current from the current source and to thereby the slope of the saw-tooth wave from the saw-tooth wave generating means.

Frequency-voltage converter

Growing community of inventors

Kodaira, Japan

Norihisa Yamamoto