LTC1755 Datasheet, PDF (1/12 Pages) Linear Technology – Smart Card Interface

FEATURES
s _{Fully ISO 7816-3 and EMV Compliant}
(Including Auxiliary I/O Pins)
s _{Buck-Boost Charge Pump Generates 3V or 5V}
s _{2.7V to 6.0V Input Voltage Range}
s _{Very Low Operating Current: 60µA}
s _{> 10kV ESD on All Smart Card Pins}
s _{Dynamic Pull-Ups Deliver Fast Signal Rise Times}
s _{Soft Start Limits Inrush Current at Turn On}
s _3V ↔ _{5V Signal Level Translators}
s _{Shutdown Current: < 1µA}
s _{Short-Circuit and Overtemperature Protected}
s _{Alarm Output Indicates Fault Condition}
s _{Multiple Devices May Be Paralleled for}
Multicard Applications
s _{Available in 24-Pin SSOP Package}
U
APPLICATIONS
s _{Handheld Payment Terminals}
s _{Pay Telephones}
s _ATMs
s _{Key Chain Readers}
s _{Smart Card Readers}
Final Electrical Specifications
LTC1755
Smart Card Interface
October 1999
DESCRIPTION
The LTC^®1755 universal Smart Card interface is fully
compliant with ISO 7816-3 and EMV specifications. It
provides the smallest and simplest interface circuit be-
tween a host microcontroller and general purpose Smart
Cards.
An internal charge pump DC/DC converter delivers regu-
lated 3V or 5V to the Smart Card, while on-chip level
shifters allow connection to a low voltage controller. All
Smart Card contacts are rated for 10kV ESD, eliminating
the need for external ESD protection devices.
Input voltage may range from 2.7V to 6.0V, allowing direct
connection to a battery. Automatic DC/DC converter soft
start mitigates start-up problems that may result when the
input power is provided by another regulator. Multiple
LTC1755 devices may be paralleled and connected to a
single controller for multicard applications.
Battery life is maximized by 60µA operating current and
1µA shutdown current. The 24-pin SSOP package mini-
mizes PCB area for compact portable systems.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
3.3V
SMART CARD
PRESENT SWITCH
C3
10µF
GND V_CC
AUX1
SMART CARD
AUX2
I/O
RST
CLK
1
PRES
24
5V/3V
2
PWR
23
CARD
3
CS
22
ALARM
4
21
NC/NO READY
C2
10µF
5
20
GND
DV_CC
6 _{VIN LTC1755 C –} 19
7
V_CC
C ^{+ 18}
8
17
AUX1 AUX1IN
9
16
AUX2 AUX2IN
10
I/O
15
DATA
11
RST
14
RIN
12
CLK
13
CIN
C1
0.68µF
µCONTROLLER
1755 TA01
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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