Editing Smart card (section)

==== Contact smart cards ====
[[File:Smartcard chip structure and packaging EN.svg|thumb|Illustration of smart-card structure and packaging]]
[[File:Sim Chip.jpg|thumb|4 by 4 mm silicon chip in a SIM card, which was peeled open. Note the thin gold bonding wires and the regular, rectangular digital-memory areas.]]
[[File:SmartCardPinout.svg|thumb|A smart-card [[pinout]]. '''VCC''': [[IC power supply pin|Power supply]]. '''RST''': Reset signal, used to reset the card's communications. '''CLK''': Provides the card with a [[clock signal]], from which data communications timing is derived. '''GND''': [[Ground (electricity)|Ground]] (reference voltage). '''VPP''': ISO/IEC 7816-3:1997 designated this as a programming voltage: an input for a higher voltage to program persistent memory (e.g., [[EEPROM]]). ISO/IEC 7816-3:2006 designates it SPU, for either standard or proprietary use, as input and/or output. '''I/O''': Serial input and output ([[half-duplex]]). '''C4, C8''': The two remaining contacts are AUX1 and AUX2 respectively and are used for [[USB]] interfaces and other uses.<ref>[http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=36576 ISO/IEC 7816-2:1999/Amd 1:2004 ''Assignment of contacts C4 and C8''] {{Webarchive|url=https://web.archive.org/web/20120315031835/http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=36576 |date=15 March 2012 }}.</ref> However, the usage defined in ISO/IEC 7816-2:1999/Amd 1:2004 may have been superseded by ISO/IEC 7816-2:2007.<ref>[http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=45989 ISO/IEC 7816-2:2007. Identification cards – Integrated circuit cards – Part 2: Cards with contacts – Dimensions and location of the contacts] {{Webarchive|url=https://web.archive.org/web/20160304093036/http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=45989 |date=4 March 2016 }}.</ref>]]

[[File:Differentsmartcardpadlayouts.jpg|thumb|Contact-type smart cards may have many different [[contact pad]] layouts, such as these [[Subscriber identity module|SIMs]].]]
Contact smart cards have a contact area of approximately {{convert|1|cm2}}, comprising several gold-plated [[contact pad]]s. These pads provide electrical connectivity when inserted into a [[Card reader|reader]],<ref>{{cite web|title=About Smart Cards: Introduction: Primer|url=http://www.smartcardalliance.org/smart-cards-intro-primer/|publisher=Secure Technology Alliance|access-date=7 August 2017|archive-date=27 March 2018|archive-url=https://web.archive.org/web/20180327135443/http://www.smartcardalliance.org/smart-cards-intro-primer/|url-status=live}}</ref> which is used as a communications medium between the smart card and a host (e.g., a computer, a point of sale terminal) or a mobile telephone. Cards do not contain [[Battery (electricity)|batteries]]; power is supplied by the card reader.

The [[ISO/IEC 7810]] and [[ISO/IEC 7816]] series of standards define:
* physical shape and characteristics,
* electrical connector positions and shapes,
* electrical characteristics,
* [[communications protocol]]s, including commands sent to and responses from the card,
* basic functionality.

Because the chips in financial cards are the same as those used in [[subscriber identity module]]s (SIMs) in mobile phones, programmed differently and embedded in a different piece of [[Polyvinyl chloride|PVC]], chip manufacturers are building to the more demanding GSM/3G standards. So, for example, although the EMV standard allows a chip card to draw 50&nbsp;mA from its terminal, cards are normally well below the telephone industry's 6&nbsp;mA limit. This allows smaller and cheaper financial card terminals.

Communication protocols for contact smart cards include T=0 (character-level transmission protocol, defined in ISO/IEC 7816-3) and T=1 (block-level transmission protocol, defined in ISO/IEC 7816-3).