Linear Technology LTC 4557 Quick Start Manual

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 709
DESCRIPTION
The LTC ® 4557 provides power conversion and signal
level translation needed for 2.5G and 3G cellular tele-
phones to interface with 1.8V or 3V subscriber iden-
tity modules (SIMs). The part meets all requirements
for 1.8V and 3V SIMs. The part contains LDO regula-
tors to power 1.8V or 3V SIM cards from a 2.7V to
5.5V input. The output voltages can be set using the
two voltage selection pins and up to 50mA of load
current can be supplied. Internal level translators al-
QUICK START PROCEDURE
TM
The QuickEval (ltcqev.exe) software can be run
from the supplied CD-ROM or by downloading it
from www.linear.com. Follow the DC590A Quick
Plug the supplied USB cable into your computer
1.
and then into the DC590A controller board.
Run the ltcqev.exe program and the window be-
2.
low should appear.
DUAL SIM/SMART CARD POWER SUPPLY AND INTERFACE
low controllers operating with supplies as low as 1.2V
to interface with 1.8V or 3V smart cards. Battery life
is maximized by a low operating current of less than
100µA and a shutdown current of less than 1µA.
Design files for this circuit board are available. Call
the LTC factory.
LTC is a trademark of Linear Technology Corporation
Start Procedure for software installation instruc-
tions.
3.
4.
Make certain that the three jumpers on the
DC709 are set to "INT."
Attach the Ribbon cable from the DC590A to the
DC709. Pin 1 is identified on the ribbon cable by
a red mark. See photo below.
LTC4557
1