LTC1555L-1.8 Datasheet, PDF (1/8 Pages) Linear Technology – SIM Power Supply and Level Translator

LTC1555L-1.8
SIM Power Supply and
Level Translator
FEATURES
s _{Buck/Boost Charge Pump Generates 1.8V, 3V or 5V}
s _{Input Voltage Range: 2.6V to 6V}
s _{Controller VCC Range: 1.425V to 4.4V}
s _{>10kV ESD on All SIM Contact Pins}
s _{Short-Circuit and Overtemperature Protected}
s _{Meets all ETSI and IMT-2000 SIM Interface}
Requirements
s _{1.8V to 5V Signal Level Translators}
s _{Very Low Operating Current: 32µA}
s _{Very Low Shutdown Current: <1µA}
s _{Soft-Start Limits Inrush Current at Turn-On}
s _{1MHz Switching Frequency}
s _{Available in 16-Pin Narrow SSOP Package}
U
APPLICATIO S
s _{SIM Interface in GSM Cellular Telephones}
s _{WCDMA SIM Interface}
s _{Smart Card Readers}
DESCRIPTIO
The LTC^®1555L-1.8 provides power conversion and level
shifting needed for low voltage GSM and WCDMA cellular
telephones to interface with either 1.8V, 3V or 5V sub-
scriber identity modules (SIMs). The part contains a
patented buck/boost charge pump DC/DC converter* that
delivers a regulated V_CC supply voltage to the SIM card.
Input voltage may range from 2.6V to 6V allowing direct
connection to the battery. The output voltage may be
programmed to 1.8V, 3V, 5V or direct connection to the
V_IN pin.
Internal level translators allow controllers operating with
supplies as low as 1.425V to interface with 1.8V, 3V and
5V SIMs. A soft-start feature limits inrush current at turn-
on, mitigating start-up problems that may result when the
input is supplied by another low-power DC/DC converter.
Battery life is maximized by 32µA operating current, and
1µA shutdown current. Board area is minimized by the
miniature 16-pin narrow SSOP packages and the need for
only three small external capacitors.
, LTC and LT are registered trademarks of Linear Technology Corporation.
*U.S. Patent No.: 5,973,944
TYPICAL APPLICATIO
GSM Cellular Telephone SIM Interface
GSM
CONTROLLER
V_CC
1.425V TO 4.4V LTC1555L-1.8
1
CIN
2
RIN
3
DATA
4
DDRV
5
DV_CC
6
M2
7
M1
8
M0
16
CLK
15
RST
14
I/O
13
V_CC
12
V_IN
C1^{+ 11}
C1^{– 10}
9
GND
V_IN
2.6V TO 6V
0.1µF
1µF
SIM
CLK
RST
I/O
V_CC = 1.8V,3V,5V
I_VCC = 10mA
2.2µF
GND
1555L TA01
1