Mobile data carrier with data-independent supply current and voltage

• US 6,996,726 B1
• Filed: 12/24/1999
• Issued: 02/07/2006
• Est. Priority Date: 01/07/1999
• Status: Expired due to Term

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Den Besten, Gerrit W., Timm, Volker, Kessels, Jozef L.W.
• Primary Examiner(s): Cao, Chun
• Application Number:
  US09/623,643
• Time in Patent Office: 2,237 Days
• Field of Search: 713/300, 713/320, 323/220, 323/224, 323/268, 235/492
• US Class Current: 713/300
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/07363 by preventing analysis of the circuit, e.g. dynamic or static power analysis or current analysis

Abstract

Disclosed is a mobile data carrier comprising a data-processing circuit; and a supply unit (1) to apply electric energy to power supply terminals for operating the data-processing circuit from an external energy source and (2) controlling voltage and current at external access points of the data carrier, wherein the supply unit including a voltage-limiting control circuit arranged in parallel to the power supply terminals of the data-processing circuit, and a current control device which, with respect to the supply of energy to the data-processing circuit, is arranged in series with the parallel arrangement of the voltage-limiting control circuit and the data-processing circuit.

Claims

1. A mobile data carrier comprising:

a data-processing circuit that includes asynchronously operating logic elements whose signal-processing rate is dependent on a power supply voltage applied to the data-processing circuit,

a voltage regulator, operably coupled in parallel with the data-processing circuit, that is configured to control the power supply voltage applied to the data-processing circuit, and

a current source, operably coupled in series between the data-processing circuit and a power source that is configured to provide a supply current to the data-processing circuit and the voltage regulator, wherein

the current source includes;

a first transistor that includes;

a gate that is connected to a first node of the power source,

a drain through which a first current flows, and

a source that is connected to a second node of the power source, and

a current mirror that is configured to provide a multiple of the first current as the supply current.

2. The mobile data carrier of claim 1, wherein

the current mirror includes a second transistor and a third transistor having commonly connected gates.