LTC4556
Smart Card Interface
with Serial Control
FEATURES
s
s
DESCRIPTIO
s
s
s
s
s
s
s
s
s
s
Electrical Specifications Are ISO7816-3 and EMV
Compatible
Control/Status Serial Port May be Daisy-Chained
for Multicard Applications
Automatic Shutdown on Electrical Faults
Buck Boost Charge Pump Generates 5V, 3V or 1.8V
Outputs (Smart Card Classes A, B and C)
Automatic Level Translation
Dynamic Pull-Ups Deliver Fast Signal Rise Times*
Supervisory Functions Prevent Smart Card Faults
Low Operating Current: 250µA Typical
V
IN
: 2.7V to 5.5V
Ultralow Shutdown Current
>10kV ESD on Smart Card Pins
Small 24-Pin 4mm
×
4mm QFN Package
The LTC
®
4556 provides all necessary power control, level
translation and supervisory functions for a smart card or
S.A.M. card interface. The part contains a low noise charge
pump** plus LDO for generating V
CC
power, as well as all
necessary level shifting circuitry.
The card voltage can be set to either 1.8V, 3V or 5V. The
LTC4556 includes a card detection channel with automatic
debounce circuitry. To reduce wiring costs, the LTC4556
interfaces to a microcontroller via a simple 4-wire serial
interface. Multiple devices may be connected in daisy-
chain fashion so that the number of wires to the card
socket board is independent of the number of sockets.
Status data is returned over the same interface.
Extensive security features ensure proper deactivation
sequencing in the event of a supply fault or a smart card
electrical fault. The smart card pins can withstand greater
than 10kV ESD in-situ with no additional components.
The LTC4556 is available in a small, low profile (0.75mm),
4mm
×
4mm QFN package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
*U.S. Patent No. 6,356,140
**U.S. Patent No. 6,411,531
APPLICATIO S
s
s
s
s
s
s
Handheld Payment Terminals
Pay Telephones
ATM Machines
POS Terminals
Computer Keyboards
Multiple S.A.M. Sockets
TYPICAL APPLICATIO
240k
1
10
INPUT
POWER
0.1µF
1µF
8
6
21
4-WIRE
COMMAND
INTERFACE
22
23
24
DV
CC
V
BATT
180k
20
UNDERV
PRES
LTC4556
19
GND
FAULT
D
IN
D
OUT
SCLK
LD
C8
C4
I/O
RST
CLK
V
CC
18
17
16
15
14
13
1µF
4556
TA01
SMART CARD
2
4-WIRE
CARD
INTERFACE
3
4
5
DATA
R
IN
SYNC
ASYNC
C
+
C
–
11
9
CPO
12
1µF
1µF
U
Deactivation Sequence
RST
5V/DIV
CLK
5V/DIV
I/O
5V/DIV
V
CC
5V/DIV
10µs/DIV
4556 G11.eps
U
U
4556f
1
LTC4556
ABSOLUTE
AXI U RATI GS
V
BATT
, DV
CC
, CPO, FAULT,
UNDERV to GND ....................................... –0.3V to 6.0V
PRES, DATA, R
IN
, SYNC, ASYNC,
LD, D
IN
, SCLK to GND ............... –0.3V to (DV
CC
+ 0.3V)
I/O, CLK ....................................... –0.3V to (V
CC
+ 0.3V)
PACKAGE/ORDER I FOR ATIO
TOP VIEW
UNDERV
PRES
SCLK
D
OUT
D
IN
LD
24 23 22 21 20 19
DV
CC
1
DATA 2
R
IN
3
SYNC 4
ASYNC 5
FAULT 6
7
NC
25
8
GND
9 10 11 12
C
–
V
BATT
+
CPO
UF PACKAGE
24-LEAD (4mm
×
4mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 37°C/W
EXPOSED PAD (PIN 25) IS SGND.
MUST BE SOLDERED TO PCB
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
BATT
= 3.3V, DV
CC
= 3.3V unless otherwise noted.
PARAMETER
Input Power Supply
V
BATT
Operating Voltage
I
VBATT
Operating Current
I
VBATT
Shutdown Current
DV
CC
Operating Voltage
I
DVCC
Operating Current
I
DVCC
Shutdown Current
Charge Pump
R
OLCP
5V Mode Open-Loop
Output Resistance
CPO Turn On Time
V
BATT
= 3.075V, I
CPO
= I
CC
= 60mA, (Note 3)
I
CC
= 0mA, 10% to 90%
q
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
C
V
CC
= 5V, I
CC
= 0µA
No Card Present, V
CPO
= 0V
2
U
U
W
W W
U
W
(Note 1)
I
CC
(Note 5) .......................................................... 65mA
V
CC
Short-Circuit Duration ............................... Indefinite
Operating Temperature Range (Note 4) .. – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 125°C
ORDER PART
NUMBER
LTC4556EUF
18 C8
17 C4
16 I/O
15 RST
14 CLK
13 V
CC
UF PART
MARKING
4556
MIN
2.7
TYP
MAX
5.5
UNITS
V
µA
µA
V
µA
µA
Ω
ms
q
q
q
q
q
250
0.5
1.7
5
0.2
8.2
0.6
400
1.75
5.5
25
1.5
17
1.5
4556f
LTC4556
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
BATT
= 3.3V, DV
CC
= 3.3V unless otherwise noted.
SYMBOL
Smart Card Supply
V
CC
Output Voltage
5V Mode, 0 < I
CC
< 60mA
3V Mode, 0 < I
CC
< 50mA
1.8V Mode, 0 < I
CC
< 30mA
I
CC
= 0mA, 10% to 90%
Relative to Nominal Output
q
q
q
q
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
MIN
4.65
2.75
1.65
–9
60
15
TYP
5.0
3.0
1.8
0.8
–5
110
32
1
100
MAX
5.35
3.25
1.95
1.5
– 2.5
150
60
2.5
250
0.2
UNITS
V
V
V
ms
%
mA
ms
µA
µs
V
V
ns
MHz
V
CC
Turn On-Time
Undervoltage Detection
Overcurrent Detection
Smart Card Detection
Debounce Time (
Deactivation Time (
PRES to
D7)
q
PRES Pull-Up Current
RST to V
CC
= 0.4V)
CLK (Non-Bidirectional Modes)
Low Level Output Voltage (V
OL
), (Note 2)
High Level Output Voltage (V
OH
), (Note 2)
Rise/Fall Time, (Note 2)
CLK Frequency, (Note 2)
RST, C4, C8
Low Level Output Voltage (V
OL
), (Note 2)
High Level Output Voltage (V
OH
), (Note 2)
Rise/Fall Time, (Note 2)
Low Level Output Voltage (V
OL
), (Note 2)
High Level Output Voltage (V
OH
), (Note 2)
Rise/Fall Time, (Note 2)
Short Circuit Current, (Note 2)
Low Level Output Voltage (V
OL
)
High Level Output Voltage (V
OH
)
Rise/Fall Time
Low Input Threshold (V
IL
)
High Input Threshold (V
IH
)
Input Current (I
IH
/I
IL
)
D
OUT
Low Level Output Voltage (V
OL
)
High Level Output Voltage (V
OH
)
UNDERV
Threshold
Leakage Current
V
PRES
= 0
I
CC
= 0mA, C
VCC
= 1µF
Sink Current = – 200µA
Source Current = 200µA
Loaded with 50pF, 10% to 90%
q
q
q
q
q
q
V
CC
– 0.2
16
10
0.2
V
CC
– 0.2
100
0.3
0.85 • V
CC
500
5
10
0.3
0.8 • DV
CC
500
0.15 • DV
CC
0.85 • DV
CC
–1
1
0.3
DV
CC
– 0.3
1.17
1.23
1.29
50
Sink Current = – 200µA
Source Current = 200µA
Loaded with 50pF, 10% to 90%
Sink Current = –1mA (V
DATA
= 0V or V
SYNC
= 0V)
Source Current = 20µA (V
DATA
= V
DVCC
or
V
SYNC
= V
DVCC
)
Loaded with 50pF, 10% to 90%
V
DATA
= 0V or V
SYNC
= 0V
Sink Current = – 500µA (V
I/O
= 0V or V
CLK
= 0V)
Source Current = 20µA (V
I/O
= V
CC
or V
CLK
= V
CC
)
Loaded with 50pF
q
q
q
V
V
ns
V
V
ns
mA
V
V
ns
V
V
µA
V
V
V
nA
I/O, CLK (CLK Specifications in Bidirectional Mode Only)
q
q
q
q
DATA, SYNC (SYNC Specifications in Bidirectional Mode Only)
q
q
q
R
IN
, D
IN
, SCLK, LD, SYNC, ASYNC (SYNC Specifications for Non-Bidirectional Mode)
q
q
q
Sink Current = – 200µA
Source Current = 200µA
q
q
q
V
UNDERV
= 3.3V
q
4556f
3
LTC4556
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
BATT
= 3.3V, DV
CC
= 3.3V unless otherwise noted.
PARAMETER
FAULT
Low Level Output Voltage (V
OL
)
Leakage Current
Serial Port Timing
t
DS
t
DH
t
DD
t
L
t
H
t
LW
t
CL
t
LC
D
IN
Valid to SCLK Setup
D
IN
Valid to SCLK Hold
D
OUT
Output Delay
SCLK Low Time
SCLK High Time
LD Pulse Width
SCLK to LD
LD to SCLK
C
LOAD
= 15pF
8
8
15
50
50
50
50
0
60
ns
ns
ns
ns
ns
ns
ns
ns
Sink Current = – 200µA
V
FAULT
= 5.5V
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
MIN
TYP
0.005
MAX
0.3
1
UNITS
V
µA
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
This specification applies to all three smart card voltage classes:
1.8V, 3V and 5V.
Note 3:
R
OLCP
≡
(2V
BATT
– V
CPO
)/I
CPO
; V
CPO
will depend upon total load
(I
CC
) and minimum supply voltage V
BATT
. See Figure 6.
Note 4:
The LTC4556E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the – 40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 5:
Based on long term current density limitation.
TYPICAL PERFOR A CE CHARACTERISTICS
No Load Supply Current vs V
BATT
500
SHORT-CIRCUIT CURRENT (mA)
T
A
= 25°C
I
CC
= 0µA
6.0
DV
CC
= V
BATT
= 3.3V
V
CC
= 5V
OUTPUT RESISTANCE (Ω)
9
400
SUPPLY CURRENT (µA)
300
V
CC
= 5V
V
CC
= 3V
200
V
CC
= 1.8V
100
0
2.7
3.1
3.9 4.3 4.7 5.1
V
BATT
SUPPLY VOLTAGE (V)
3.5
4
U W
5.5
4556 G01
I/O and CLK Short-Circuit Current
vs Temperature
(CLK in Bidirectional Mode)
10
Charge Pump Open-Loop Output
Resistance vs Temperature
(2V
BATT
– V
CPO
) / I
CPO
V
BATT
= 2.7V
V
CPO
= 4.9V
5.5
5.0
CLK
I/O
8
4.5
7
4.0
3.5
–40
–15
10
35
TEMPERATURE (°C)
60
85
4556 G02
6
–40
–15
10
35
TEMPERATURE (°C)
60
85
4556 G03
4556f
LTC4556
TYPICAL PERFOR A CE CHARACTERISTICS
V
CC
Overcurrent Shutdown
Threshold vs Temperature
140
V
BATT
= 3.3V
130
LOAD CURRENT (mA)
120
V
CC
= 5V, CPO = 5.5V
110
100
90
80
–40
V
CC
= 3V, CPO = 5.5V
V
CC
= 1.8V, CPO = 4V
DEBOUNCE TIME (ms)
45
T
A
= 85°C
I/O LOW OUTPUT VOLTAGE (mV)
–15
10
35
TEMPERATURE (°C)
Extra Input Current vs
Load Current (I
BATT
– 2I
CC
)
6
5
4
3
2
1
0
0.01
V
BATT
= 3.3V
T
A
= 25°C
EXTRA INPUT CURRENT (mA)
SUPPLY CURRENT (µA)
2.0
T
A
= 25°C
1.5
1.0
T
A
= –40°C
SUPPLY CURRENT (µA)
0.1
1
10
LOAD CURRENT (mA)
Charge Pump and LDO Activation
RST
5V/DIV
V
CPO
5V/DIV
V
CC
5V/DIV
I/O
5V/DIV
1ms/DIV
4556 G10
U W
60
85
4556 G04
Card Detection Debounce Time vs
V
BATT
Supply Voltage
50
200
Bidirectional Channel (I/O) Low
Output Level vs Temperature
V
DATA
= V
SYNC
= 0V
I
OL
= –1mA
V
BATT
= 3V
175
V
CC
= 1.8V
40
T
A
= 25°C
T
A
= –40°C
150
V
CC
= 3V, 5V
35
125
30
25
2.7
3.1
3.9 4.3 4.7 5.1
V
BATT
SUPPLY VOLTAGE (V)
3.5
5.5
100
–40
–15
10
35
TEMPERATURE (°C)
60
85
4556 G06
4556 G05
V
BATT
Shutdown Current vs
Supply Voltage
3.0
V
DVCC
= V
BATT
2.5
DV
CC
Shutdown Current vs Supply
Voltage
1.0
V
BATT
= V
DVCC
0.8
0.6
T
A
= 25°C
0.4
T
A
= –40°C
T
A
= 85°C
T
A
= 85°C
0.5
0
2.7
0.2
100
4556 G07
3.1
3.9 4.3 4.7 5.1
V
BATT
SUPPLY VOLTAGE (V)
3.5
5.5
0
2.7
3.1
3.5 3.9 4.3 4.7 5.1
V
DVCC
SUPPLY VOLTAGE (V)
5.5
4556 G08
4556 G09
Deactivation Sequence
Data – I/O Channel
CLK
5V/DIV
I/O
5V/DIV
V
CC
5V/DIV
I/O
2V/DIV
DATA
2V/DIV
10µs/DIV
4556 G11.eps
100ns/DIV
4556 G12
4556f
5
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