Datasheet Linear Technology LTC1955

Manufacturer	Linear Technology
Series	LTC1955

Dual Smart Card Interface with Serial Control

Datasheets

PDF, 374 Kb, Revision: D, File uploaded: Nov 16, 2017

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Prices

Packaging

	LTC1955EUH#PBF	LTC1955EUH#TRPBF	LTC1955IUH#PBF	LTC1955IUH#TRPBF
N	1	2	3	4
Package	5x5 QFN-32 Package Outline Drawing	5x5 QFN-32 Package Outline Drawing	5x5 QFN-32 Package Outline Drawing	5x5 QFN-32 Package Outline Drawing
Package Code	UH	UH	UH	UH
Package Index	05-08-1693	05-08-1693	05-08-1693	05-08-1693
Pin Count	32	32	32	32

Parametrics

Parameters / Models	LTC1955EUH#PBF	LTC1955EUH#TRPBF	LTC1955IUH#PBF	LTC1955IUH#TRPBF
Demo Boards	DC465A	DC465A	DC465A	DC465A
Export Control	no	no	no	no
Isupply, mA	0.25	0.25	0.25	0.25
Operating Temperature Range, °C	0 to 85	0 to 85	-40 to 85	-40 to 85
Output Current, A	0.05	0.05	0.05	0.05
Output Voltage	1.8V,3.0V,5.0V	1.8V,3.0V,5.0V	1.8V,3.0V,5.0V	1.8V,3.0V,5.0V
Vin Max, V	6	6	6	6
Vin Min, V	3	3	3	3

Eco Plan

	LTC1955EUH#PBF	LTC1955EUH#TRPBF	LTC1955IUH#PBF	LTC1955IUH#TRPBF
RoHS	Compliant	Compliant	Compliant	Compliant

Design Notes

Download
Single Interface Chip Controls Two Smart Cards &mdash DN289
PDF, 95 Kb, File published: Jul 1, 2002
Extract from the document
Single Interface Chip Controls Two Smart Cards вЂ“ Design Note 289
Steven Martin
Introduction
There are considerable challenges to smart card interfacing, including various voltage levels (both input and
output) and stringent fault handling requirements. To
produce a robust card reading system, designers must
comply with extensive and often difп¬Ѓcult software as
well as hardware standards. Furthermore, there are
other complications like in-circuit ESD and pin-to-pin
shorts to contend with.
The LTC В®1955 dual smart card interface provides all
of the required power management, control, ESD and
fault detection circuitry for two smart cards. Employing
a voltage doubling charge pump and two low dropout
linear regulators, this device generates two independent levels of either 5V, 3V or 1.8V from a 2.7V to 5.5V input. Both channels have the required pins to support
the EMV (Europay, MasterCard, Visa) and the ISO7816
smart card standards. One channel has extra control
pins (smart card contact pad locations C4 and C8)
to support existing memory cards. The entire chip is
controlled by a microcontroller-friendly serial interface.
Features
The LTC1955 includes considerable security and functionality, yet remains easy to use. Two independent
circuits detect the presence or absence of a smart …

Articles

Download
Dual Smart Card Interface Simplifies Multicard Reader Designs &mdash LT Journal
PDF, 355 Kb, File published: Mar 1, 2003
Extract from the document
DESIGN FEATURES Dual Smart Card Interface Simplifies
by Steven Martin
Multicard Reader Designs
Introduction
The LTC1955 dual smart card interface provides a complete and compact
solution for multicard applications.
The LTC1955 and five small capacitors
are all that are needed to interface two
card sockets to a host microcontroller.
Designed to comply with all smart card
standards, the LTC1955 can be used
for full sized card sockets, smaller
vendor card (simlock) sockets, or any
combination of smart card and vendor
card sockets. Figure 1 shows the block diagram
of the LTC1955, which operates from
a battery or a regulated 3.3V supply.
The internal charge pump delivers
a boosted voltage to two on-chip
low dropout regulators. The LDOs
provide programmable 1.8V, 3V or
5V regulated outputs to each of the
smart card sockets. Two unidirectional channels and one bi-directional …

Model Line

Series: LTC1955 (4)

LTC1955EUH#PBF LTC1955EUH#TRPBF LTC1955IUH#PBF LTC1955IUH#TRPBF

Manufacturer's Classification

Interface > SIM Interface

EMS supplier

Slices

Microcontrollers