Very high frequency transponder, in particular a UHF transponder, including a protection against electrostatic discharges

• US 7,598,843 B2
• Filed: 12/15/2005
• Issued: 10/06/2009
• Est. Priority Date: 12/16/2004
• Status: Active Grant

• Current Assignee: EM Microelectronic - Marin SA (The Swatch Group AG)
• Original Assignee: EM Microelectronic - Marin SA (The Swatch Group AG)
• Inventors: Pardoen, Matthijs
• Primary Examiner(s): Brown; Vernal U
• Application Number:
  US11/300,347
• Publication Number:
  US 20060132221A1
• Time in Patent Office: 1,391 Days
• Field of Search: 340/10.34, 340/10.1, 340/10.4, 340/572.1, 340/572.2, 340/572.4, 340/662, 340/657, 361/56, 361/57, 361/111
• US Class Current: 340/10.1
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0715 the arrangement including means to regulate power transfer to the integrated circuit
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs

Abstract

The UHF transponder includes protection against electrostatic discharge (ESD) formed by the modulation transistor (T1) and additional control means (20) for said transistor which fulfils two functions: its first response signal modulation function and an additional ESD protection function.

Claims

1. A transponder including an antenna, a rectifier circuit, a logic circuit powered by said rectifier circuit and a modulation transistor arranged between said rectifier circuit and said logic circuit, said modulation transistor being controlled by said logic circuit to form transponder response signals, wherein it includes electrostatic discharge protection means formed by said modulation transistor and by additional means for controlling said modulation transistor arranged to put it in its non-conductive state when an electrostatic discharge leaves said rectifier circuit in the direction of said logic circuit.

2. The transponder according to claim 1, wherein said additional control means are arranged between said rectifier circuit and said modulation transistor, a logic “

OR”

gate being arranged between said additional control means and the control terminal of said modulation transistor, the additional control means sending a first control signal to a first input of said logic “

OR”

gate and said logic circuit being connected to said second input of said logic gate to which it provides a second control signal to modulate said response signals.