Seiko Epson Corporation

Noriaki Sakurada

Ichiro Kobayashi

Atsushi Yamada

Zenzo Oda

Atsushi Shinozaki

Fujikazu Sugimoto

A PC card has a plastic frame provided along the periphery of a substrate. Metal plates, such as stainless steel plates and the like, cover both surfaces of the substrate and are attached to the plastic frame. External surfaces of the metal plates located in an area on the opposite side of a connector and which are touched by a person's hand are covered by an insulation tape, so that, even if a person charged with static electricity touches the PC card when the PC card is inserted or withdrawn from an external apparatus such as a personal computer (PC), the static electricity (charge) of the person does not flow into the external apparatus. Thus, malfunctions or erroneous operations of the external apparatus do not occur.

Card-shaped electronic apparatus

Semiconductor memory device with enable signal conversion circuit

An objective of the present invention is to provide a highly reliable IC card which is large in the scale of integration, fast, and low power-consuming, which contains the latest type of IC that has an operating voltage of 3.3 V and a maximum rated voltage of 5 V or less, and which can be used in either the latest equipment rated at 3.3 V or existing equipment rated at 5 V, or which does not cause this latest type of IC to be destroyed. The interface circuit comprises an analog switch, an external interface circuit, an interval interface circuit, and a high-voltage detection circuit. If the voltage of the power supply Vcc of the host system is less than or equal to an upper-limit voltage of 4 V, the power supply voltage is applied unchanged through the analog switch to a ROM that is the main circuit. On the other hand, if the power supply voltage is greater than this upper-limit voltage of 4 V, the analog switch is made non-conductive and thus the power supply voltage is not applied to the ROM. This prevents the ROM from being destroyed. If a regulated-voltage circuit is also provided, a power supply voltage regulated at 3.3 V can be applied to the ROM, even when the power supply voltage of host system is greater than the upper-limit voltage of 4 V.

IC card with dual level power supply interface and method for operating

A dynamic access random access card is provided with a dynamic random access memory and a source for generating a plurality of reference clock pulses. A control circuit generates refresh operations of the dynamic access memory in response to the plurality of reference clock pulses generated by the source, the initiation of the refresh operations being independent of any external refresh request. The refresh operations are interrupted and the dynamic random access memory is set to a standby condition upon detection of a predetermined external signal, thereby permitting read/write operations of the dynamic random access memory.

Memory card having controller providing adjustable refresh to a

Memory card with control and voltage boosting circuits and electronic

Growing community of inventors

Suwa, Japan

Noriaki Sakurada