ltc4558eud-trpbf Linear Technology Corporation, ltc4558eud-trpbf Datasheet - Page 6

• Manufacturer Part Number: ltc4558eud-trpbf
• Description: Dual Sim/smart Card Power Supply And Interface
• Manufacturer: Linear Technology Corporation

PIN FUNCTIONS
LTC4558
DV
logic.
V
tions of the LTC4558.
V
should be connected to the V
sockets. The activation of the V
by ENABLEA and ENABLEB. They can be set to 1.8V or 3V
via the VSELA and VSELB inputs.
CLKA,CKLB (Pins 5, 20): Card Socket. The CLKA,CKLB
pins should be connected to the CLK pins of the respective
card sockets. The CLKA,CKLB signals are derived from the
CLKIN pin. They provide a level shifted CLKIN signal to
the selected card. The CLKA,CKLB pins are gated off until
V
is deselected, its CLK pin may be left active or brought
LOW using the CLKRUNA, CLKRUNB pins.
RSTA,RSTB (Pins 6, 19): Card Socket. The RSTA,RSTB
pins should be connected to the RST pins of the respec-
tive card sockets. The RSTA,RSTB signals are derived
from the RSTIN pin. When a card is selected, its RST
pin follows RSTIN. The RSTA,RSTB pins are gated off
until V
socket is deselected, the state of its RST pin is latched to
its current state.
I/OA,I/OB (Pins 7, 18): Card Socket. The I/OA,I/OB pins
should be connected to the I/O pins of the respective card
sockets. When a card is selected, its I/O pin transmits/re-
ceives data to/from the DATA pin. The I/OA,I/OB pins are
gated off until V
DATA (Pin 8): Input/Output. Microcontroller side data I/O
pin. The DATA pin provides the bidirectional communication
6
BATT
CCA
CCA
CC
,V
,V
(Pin 2): Power. Reference voltage for the control
(Pin 3): Power. Supply voltage for the analog sec-
CCA
CCB
CCB
,V
attain their correct values. When a card socket
(Pins 4, 1): Card Socket. The V
CCB
CCA
attain their correct values. When a card
,V
CCB
attain their correct values.
CC
CCA
pins of the respective card
,V
CCB
pins are controlled
CCA
,V
CCB
pins
path to both cards. One of the cards may be selected to
communicate via the DATA pin at a time. The pin possesses
a weak pull-up current source, allowing the controller to
use an open drain output and maintain a HIGH state during
shutdown, as long as DV
RSTIN (Pin 9): Input. The RSTIN pin supplies the reset
signal to the cards. It is level shifted and transmitted
directly to the RST pin of the selected card.
CLKIN (Pin 10): Input. The CLKIN pin supplies the clock
signal to the cards. It is level shifted and transmitted di-
rectly to the CLK pin of the selected card. If CLKRUNA,B
is HIGH, the clock signal will be transmitted to the CLKA,B
pin, regardless of whether that card is selected, as long
as that card socket is enabled.
ENABLEA, ENABLEB (Pins 11, 17): Inputs. The ENABLEA
and ENABLEB pins enable or disable channel A and chan-
nel B, respectively.
VSELA, VSELB (Pins 12, 16): Inputs. The VSELA and
VSELB pins select the voltage level of each set of SIM/
Smart Card pins. Bringing either of these pins HIGH will
set the output level of its respective channel to 3V. Bring-
ing either of these pins LOW will set the output level of
its respective channel to 1.8V.
CSEL (Pin 13): Input. The CSEL pin selects which set of
SIM/Smart Card pins are active.
CLKRUNA, CLKRUNB (Pins 14, 15): Inputs. The CLKRUNA
and CLKRUNB inputs are used to select whether the clock
signal is always sent to card sockets that are enabled or
whether the clock is gated with the CSEL pin.
Exposed Pad (Pin 21): Ground. This ground pad must be
soldered directly to a PCB ground plane.
CC
is powered.
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