mic4555 Micrel Semiconductor, mic4555 Datasheet - Page 11

• Manufacturer Part Number: mic4555
• Description: Sim Card Level Shifter With 50ma Ldo
• Manufacturer: Micrel Semiconductor

Functional Description
EN
The EN pin is the enable input from the controller. A
logic high signal enables the level shifters and the V
output. A logic low signal disables the level shifters and
the LDO and a low current shutdown mode is activated.
V
V
high logic voltage on V
A low logic voltage on V
1.8V. Do not leave floating.
DV
The DV
input and output pins (CIN, RIN, DATA). The operating
range is from 1.6V to V
capacitor with a minimum voltage rating of 6.3V placed
close to DV
Layout Recommendations for details.
V
The V
operating range is from 2.7V to 5.5V. A minimum 1µF
input capacitor with a minimum voltage rating of 6.3V to
ground (GND) is required. Refer to the Layout
Recommendations for details.
V
The V
the SIM Card. A minimum 1µF input capacitor with a
minimum voltage rating of 6.3V to ground (GND) is
required. Refer to the Layout Recommendations for
details.
GND
The ground pin (GND) is the ground path for the biasing,
the control circuitry and the power ground. The current
loop for the ground should be kept as short as possible.
Refer to the Layout Recommendations for more details.
Micrel Inc.
January 2011
SEL
SEL
BAT
CC
CC
selects the level shifted voltage for the SIM Card. A
CC
BAT
CC
is the output of the LDO and provides power to
is the input power supply to the LDO. The
is the supply voltage for the controller side
CC
and ground (GND) is required. Refer to the
SEL
SEL
selects the level shifter to 3V.
BAT
selects the level shifter to
. A minimum 1µF input
CC
11
RIN, RST
RIN is the digital reset input for the SIM Card and
translates to RST through the digital level shifter. It is
one directional. If V
be level shifted to 1.8V at the RST output. If V
then the input at RST will be level shifted to 3V at the
RST output.
CIN, CLK
CIN is the digital input clock for SIM card. The CIN
translates to CLK and is one directional. If V
then the input at CLKIN will be level shifted to 1.8V at
the CLK output. If V
be level shifted to 3V at the CLK output.
DATA, I/O
DATA is the digital data for the SIM Card. The DATA
translate to I/O through the digital level shifter and is
bidirectional using internal pull ups. If V
the level shifted output is 1.8V at the I/O output. If V
high, then the level shifted output is 3V at the I/O output.
Since DATA and I/O are bidirectional, the input at I/O is
level shifted to equal the DV
output.
SEL
SEL
is low, then the input at RIN will
is high, then the input at CIN will
CC
voltage at the DATA
M9999-012411-A
SEL
is low, then
SEL
MIC4555
SEL
is high,
is low,
SEL
is