US 2010/0072285 A1 · Semiconductor Device and Wireless Tag Using the Same

Abstract

In a wireless tag with which a wireless communication system whose electric power of a carrier wave from a R/W is high, an overvoltage protection circuit is provided to prevent from generating excessive electric power in the wireless tag when the wireless tag receives excessive electric power. However, as noise is generated by operation of the overvoltage protection circuit, an error of reception occurs in receiving a signal whose modulation factor is small. To solve the problem, the maximum value of generated voltage in the wireless tag is held in a memory circuit after the overvoltage protection circuit operates, then the overvoltage protection circuit is controlled in accordance with the maximum value of generated voltage. The voltages at which the overvoltage protection circuit starts and stops operating are different from each other, and hysteresis occurs between the timing when the overvoltage protection circuit starts and stops operating.

Claims5

Dependent claims

A semiconductor device comprising:

a voltage detection circuit outputting a potential in accordance with a level of electric power supplied from an external portion;
a memory circuit holding a potential in accordance with a maximum value of the potential output from the voltage detection circuit;
and
a protection circuit, wherein impedance of the protection circuit is changed in accordance with the potential which is held by the memory circuit.

1 more element

Dependencies are inferred from the claim text.

Facts

Application

12/558,156Filed 11 Sep 2009

Priority

JP 2008-24149919 Sep 2008

Published

25 Mar 2010

Term ends

Not estimatedThe source records don’t support an estimate.

Classification7 codes

H10D 89/601
Integrated devices comprising arrangements for electrical or thermal protection, e.g. protection circuits against electrostatic discharge [ESD]:…
G06K 19/0707
At least one of the integrated circuit chips comprising an arrangement for power management: the arrangement being capable of collecting energy…
G06K 19/0712
At least one of the integrated circuit chips comprising an arrangement for power management: the arrangement being capable of triggering distinct…
G06K 19/0715
At least one of the integrated circuit chips comprising an arrangement for power management: the arrangement including means to regulate power…

Semiconductor Device and Wireless Tag Using the Same

Life of this patent

Semiconductor Device and Wireless Tag Using the Same

Life of this patent

Abstract

Claims5