LTC1755_15 Datasheet, PDF (1/16 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 (LTC1755)}
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 (LTC1755)
s _{Available in 16- and 24-Pin SSOP Packages}
U
APPLICATIO S
s _{Handheld Payment Terminals}
s _{Pay Telephones}
s _ATMs
s _{Key Chain Readers}
s _{Smart Card Readers}
LTC1755/LTC1756
Smart Card Interface
DESCRIPTIO
The LTC^®1755/LTC1756 universal Smart Card interfaces
are fully compliant with ISO 7816-3 and EMV specifica-
tions. The parts provide the smallest and simplest inter-
face circuits between 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. Internal soft-start mitigates start-
up problems that may result when the input power is
provided by another regulator. Multiple 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 narrow SSOP packages mini-
mize PCB area for compact portable systems.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
SMART CARD
PRESENT SWITCH
C3
10µF
GND V_CC
AUX1
SMART CARD
AUX2
I/O
RST
CLK
3.3V
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
17556 TA01
1