LTC1955 - Dual Smart Card Interface with Serial Control

Features

  • Compatible with ISO7816-3 and EMV Electrical Specifications
  • Power Management and Control for Two Smart Cards
  • Control/Status Serial Port May Be Daisychained for Multicard Applications
  • Automatic Shutdown on Electrical Faults
  • Buck/Boost Charge Pump Generates 5V, 3V or 1.8V Outputs (Smart Card Classes A, B and C)
  • Independent 5V/3V/1.8V Level Control for Both Cards
  • Automatic Level Translation
  • Supervisory Functions Prevent Smart Card Faults
  • Low Operating Current: 250μA Typical
  • Ultralow Shutdown Current
  • >10kV ESD on Smart Card Pins
  • Small 32-Lead 5mm × 5mm QFN Package
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LTC1955 Typical Application
LTC1955 Typical Application

Description

The LTC®1955 provides all necessary supervisory and power control functions for two smart cards, two S.A.M. cards or a combination of S.A.M. and smart cards. It provides a charge pump for battery-powered applications as well as all necessary level shifting circuitry.

The card voltages can be independently set to 1.8V, 3V or 5V. Both card interfaces include a card detection channel with automatic debounce circuitry. To reduce wiring costs, the LTC1955 interfaces to a microcontroller via a simple 4-wire serial interface. Multiple devices may be connected in daisychain fashion so that the number of wires to the card socket board is independent of the number of sockets. Status data is returned over the same interface.

Extensive security features ensure proper deactivation sequencing in the event of a supply fault or a smart card electrical fault. The smart card pins can withstand greater than 10kV ESD in-situ with no additional components.

The LTC1955 is available in a low profile (0.75mm) 5mm × 5mm QFN package.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC1955EUH#PBF 5x5 QFN-32 UH E 05-08-1693 Yes
LTC1955EUH#TRPBF 5x5 QFN-32 UH E 05-08-1693 Yes
LTC1955IUH#PBF 5x5 QFN-32 UH I 05-08-1693 Yes
LTC1955IUH#TRPBF 5x5 QFN-32 UH I 05-08-1693 Yes


LTC1955 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC1955EUH#PBF 5x5 QFN-32 E $3.50 $2.45 Yes
LTC1955EUH#TRPBF 5x5 QFN-32 E $2.55 Yes
LTC1955IUH#PBF 5x5 QFN-32 I $4.03 $2.82 Yes
LTC1955IUH#TRPBF 5x5 QFN-32 I $2.88 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC465A LTC1955EUH | Dual Smart Card Interface, DVCC = 3V to 5.5V, VBATT = 2.7V to 5.5V Contact Factory
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

Please contact your local sales representative for more information regarding reliability reports and AEC-Q100 data or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC1955IUH#PBF 5x5 QFN-32 I $4.03 $2.82 Yes
LTC1955IUH#TRPBF 5x5 QFN-32 I $2.88 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Applications

  • Handheld Payment Terminals
  • Pay Telephones
  • ATM Machines
  • POS Terminals
  • Computer Keyboards
  • Multiple S.A.M. Sockets

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Design Tools

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Technical Support