LTC4555_15 Datasheet, PDF (1/8 Pages) Linear Technology – SIM Power Supply and Level Translator

LTC4555
SIM Power Supply
and Level Translator
FEATURES
n _{SIM Power Supply: 1.8V/3V at 50mA}
n _{Input Voltage Range: 3V to 6V}
n _{Controller Voltage Range: 1.2V to 4.4V}
n _{14kV ESD On All SIM Contact Pins}
n _{Meets All ETSI, IMT-2000 and ISO7816 SIM/Smart}
Card Interface Requirements
n _{Level Translators to 1.8V or 3V}
n _{20μA Operating Current}
n _{Logic-Controlled Shutdown (ISD < 1μA)}
n _{Available in a Low Profile, 16-Pin (3mm × 3mm)}
QFN Package
APPLICATIONS
n _{SIM Interface in 3G Cellular Telephones}
n _{Smart Card Readers}
DESCRIPTION
The LTC^®4555 provides power conversion and signal
level shifting needed for low voltage 2.5G and 3G cellular
telephones to interface with 1.8V or 3V subscriber identity
modules (SIMs). The part meets all type approval require-
ments for 1.8V and 3V SIMs and smart cards. The part
contains an LDO linear regulator to supply SIM power at
either 1.8V or 3V from a 3V to 6V input. The output volt-
age is selected with a single pin and up to 50mA of load
current can be supplied.
Internal level translators allow controllers operating with
supplies as low as 1.2V to interface with 1.8V or 3V smart
cards. Battery life is maximized by 20μA operating current
and <1μA shutdown current. Board area is minimized by
the 3mm × 3mm leadless QFN package.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
V_CC
CONTROLLER
Typical SIM Interface
V_BAT
(1.2V TO 4.4V) (3V TO 6V)
0.1μF
DV_CC
SHDN
V_BAT
V_CC
V_SEL
LTC4555
R_IN
RST
C_IN
CLK
DATA
I/0
GND
0.1μF
SIM/
SMART CARD
INTERFACE
V_CC
1μF
RST
CLK
I/0
GND
4555 TA01
4555fb
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