
LTC1555L
5
M0
M1
OPERATING MODE
0V
Shutdown (VCC = 0V)
0V
DVCC
VCC* = VIN
DVCC
0V
VCC = 3V
DVCC
VCC = 5V
Table 1. Truth Table
*Actual VCC will depend on the output current in this mode.
N/C (Pin 6): No Internal Connection.
M1 (Pin 7): Mode Control Bit 1 (see Table 1).
M0 (Pin 8): Mode Control Bit 0 (see Table 1).
GND (Pin 9): Ground for Both the SIM and the Controller.
Should be connected to the SIM GND contact as well as to
the VIN/controller GND. Proper grounding and supply
bypassing is required to meet 15kV ESD specifications.
C1– (Pin 10): Charge Pump Flying Capacitor Negative Input.
C1+ (Pin 11): Charge Pump Flying Capacitor Positive Input.
PIN FUNCTIONS
UU
U
VIN (Pin 12): Charge Pump Input Pin. May be between
2.6V and 6V. There is no power-up sequencing require-
ment for VIN with respect to DVCC.
VCC (Pin 13): SIM Card VCC Output. Should be connected
to the SIM VCC contact. The VCC output voltage is deter-
mined by the M0-M1 pins (see Table 1). VCC is discharged
to GND during shutdown (M0, M1 = 0V). A 2.2
F low ESR
ouptut capacitor should connect close to the VCC pin.
I/O (Pin 14): SIM Side I/O Pin. The pin is an open drain
output with a nominal pull-up resistance of 10k
and
should be connected to the SIM I/O contact. The SIM card
must sink up to 1mA max when driving the I/O pin low due
to the internal pull-up resistors on the I/O and DATA pins.
The I/O pin is held active low during shutdown.
RST (Pin 15): Level Shifted Reset Output Pin. Should be
connected to the SIM RST contact.
CLK (Pin 16): Level Shifted Clock Output Pin. Should be
connected to the SIM CLK contact. Careful trace routing is
recommended due to fast rise and fall edge speeds.
BLOCK DIAGRA
W
DDRV
OPTIONAL
1
A
I/O
DATA
20k
10k
CLK
CIN
RST
DVCC
1.8V
RIN
GND
M1
M0
VIN
VBATT
CIN
1
F
VCC
I/O
CLK
RST
GND
VCC
C1+
0.1
F
C1–
STEP-UP/
STEP-DOWN
CHARGE PUMP
DC/DC
CONVERTER
SIM
CONTROLLER
VCC
COUT
2.2
F
UVLO
LTC1555L
1555L BD