Linear LTC4556EUF Schematic [ru]

FEATURES

LTC4556

Smart Card Interface

with Serial Control

DESCRIPTIO

■

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

■

VIN: 2.7V to 5.5V

■

Ultralow Shutdown Current

■

>10kV ESD on Smart Card Pins

■

Small 24-Pin 4mm × 4mm QFN Package

APPLICATIO S

■

Handheld Payment Terminals

■

Pay Telephones

■

ATM Machines

■

POS Terminals

■

Computer Keyboards

■

Multiple S.A.M. Sockets

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 VCC 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 daisychain 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

TYPICAL APPLICATIO

240k

UNDERV

INPUT

POWER

4-WIRE COMMAND INTERFACE

4-WIRE

CARD

INTERFACE

1µF0.1µF

BATT

GND

FAULT

OUT

SCLK

DATA

SYNC

ASYNC

C+C–CPO

LTC4556

1µF

180k

PRES

RST CLK

12911

I/O

15 14 13

1µF

SMART CARD

4556 TA01

RST

5V/DIV

CLK

5V/DIV

I/O

Deactivation Sequence

10µs/DIV

4556 G11.eps

4556f

LTC4556

ABSOLUTE AXI U RATI GS

, DVCC, CPO, FAULT,

BATT

(Note 1)

UNDERV to GND....................................... –0.3V to 6.0V

PRES, DATA, RIN, SYNC, ASYNC,

LD, DIN, SCLK to GND ............... –0.3V to (DVCC + 0.3V)

I/O, CLK ....................................... –0.3V to (VCC + 0.3V)

UUW

PACKAGE/ORDER I FOR ATIO

TOP VIEW

OUTDIN

SCLK

UNDERV

PRES

24 23 22 21 20 19

DATA

SYNC

ASYNC

FAULT

24-LEAD (4mm × 4mm) PLASTIC QFN

JMAX

EXPOSED PAD (PIN 25) IS SGND.

MUST BE SOLDERED TO PCB

7 8 9 10 11 12

–

GND

UF PACKAGE

= 125°C, θJA = 37°C/W

BATT

18 17 16 15 14 13

CPO

ICC (Note 5) .......................................................... 65mA

VCC 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

C8 C4 I/O RST CLK V

UF PART

MARKING

4556

Consult LTC Marketing for parts specified with wider operating temperature ranges.

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at TA = 25°C. V

PARAMETER CONDITIONS MIN TYP MAX UNITS Input Power Supply

Operating Voltage ● 2.7 5.5 V

BATT

Operating Current VCC = 5V, ICC = 0µA ● 250 400 µA

VBATT

Shutdown Current No Card Present, V

VBATT

DVCC Operating Voltage ● 1.7 5.5 V I

Operating Current ● 525µA

DVCC

Shutdown Current ● 0.2 1.5 µA

DVCC

Charge Pump

5V Mode Open-Loop V

OLCP

Output Resistance CPO Turn On Time ICC = 0mA, 10% to 90% ● 0.6 1.5 ms

= 3.075V, I

BATT

The ● denotes the specifications which apply over the full operating

= 3.3V, DVCC = 3.3V unless otherwise noted.

BATT

= 0V ● 0.5 1.75 µA

CPO

= ICC = 60mA, (Note 3) ● 8.2 17 Ω

CPO

4556f

LTC4556

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at TA = 25°C. V

The ● denotes the specifications which apply over the full operating

= 3.3V, DVCC = 3.3V unless otherwise noted.

BATT

SYMBOL CONDITIONS MIN TYP MAX UNITS Smart Card Supply

VCC Output Voltage 5V Mode, 0 < ICC < 60mA ● 4.65 5.0 5.35 V

3V Mode, 0 < I

1.8V Mode, 0 < I

< 50mA ● 2.75 3.0 3.25 V

< 30mA ● 1.65 1.8 1.95 V

VCC Turn On-Time ICC = 0mA, 10% to 90% ● 0.8 1.5 ms Undervoltage Detection Relative to Nominal Output ● –9 –5 –2.5 % Overcurrent Detection ● 60 110 150 mA

Smart Card Detection

Debounce Time ( PRES to D7) ● 15 32 60 ms PRES Pull-Up Current V Deactivation Time ( RST to VCC = 0.4V) ICC = 0mA, C

= 0 ● 1 2.5 µA

PRES

= 1µF ● 100 250 µs

VCC

CLK (Non-Bidirectional Modes)

Low Level Output Voltage (VOL), (Note 2) Sink Current = –200µA ● 0.2 V High Level Output Voltage (VOH), (Note 2) Source Current = 200µA ● VCC – 0.2 V Rise/Fall Time, (Note 2) Loaded with 50pF, 10% to 90% ● 16 ns CLK Frequency, (Note 2) ● 10 MHz

RST, C4, C8

I/O, CLK (CLK Specifications in Bidirectional Mode Only)

Low Level Output Voltage (VOL), (Note 2) Sink Current = –1mA (V High Level Output Voltage (VOH), (Note 2) Source Current = 20µA (V

= V

SYNC

DVCC

)

DATA

= 0V or V

= V

DVCC

= 0V) ● 0.3 V

SYNC

or ● 0.85 • V

Rise/Fall Time, (Note 2) Loaded with 50pF, 10% to 90% ● 500 ns Short Circuit Current, (Note 2) V

DATA

= 0V or V

= 0V ● 510mA

SYNC

DATA, SYNC (SYNC Specifications in Bidirectional Mode Only)

Low Level Output Voltage (VOL) Sink Current = –500µA (V High Level Output Voltage (VOH) Source Current = 20µA (V

= 0V or V

I/O

= VCC or V

I/O

= 0V) ● 0.3 V

CLK

= VCC) ● 0.8 • DV

CLK

Rise/Fall Time Loaded with 50pF ● 500 ns

RIN, DIN, SCLK, LD, SYNC, ASYNC (SYNC Specifications for Non-Bidirectional Mode)

Low Input Threshold (VIL) ● 0.15 • DV High Input Threshold (VIH) ● 0.85 • DV

Input Current (IIH/IIL) ● –1 1 µA

OUT

Low Level Output Voltage (VOL) Sink Current = –200µA ● 0.3 V High Level Output Voltage (VOH) Source Current = 200µA ● DVCC – 0.3 V

UNDERV

Threshold ● 1.17 1.23 1.29 V Leakage Current V

= 3.3V ● 50 nA

UNDERV

V V

4556f

LTC4556

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at TA = 25°C. V

The ● denotes the specifications which apply over the full operating

= 3.3V, DVCC = 3.3V unless otherwise noted.

BATT

PARAMETER CONDITIONS MIN TYP MAX UNITS FAULT

Low Level Output Voltage (VOL) Sink Current = –200µA ● 0.005 0.3 V Leakage Current V

= 5.5V ● 1 µA

FAULT

Serial Port Timing

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

DIN Valid to SCLK Setup 8 ns DIN Valid to SCLK Hold 8 ns D

Output Delay C

OUT

= 15pF 15 60 ns

LOAD

SCLK Low Time 50 ns SCLK High Time 50 ns LD Pulse Width 50 ns SCLK to LD 50 ns LD to SCLK 0ns

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.

OLCP

≡ (2V

BATT

– V

CPO

)/I

CPO

) and minimum supply voltage V

; V

will depend upon total load

CPO

. See Figure 6.

BATT

Note 5: Based on long term current density limitation.

TYPICAL PERFOR A CE CHARACTERISTICS

I/O and CLK Short-Circuit Current vs Temperature

No Load Supply Current vs V

500

TA = 25°C

= 0µA

400

300

200

SUPPLY CURRENT (µA)

100

2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5

VCC = 5V

VCC = 3V

VCC = 1.8V

SUPPLY VOLTAGE (V)

BATT

4556 G01

(CLK in Bidirectional Mode)

6.0 DVCC = V

5.5

5.0

4.5

4.0

SHORT-CIRCUIT CURRENT (mA)

3.5

–40

= 3.3V

BATT

= 5V

CLK

I/O

–15 10 35 60 85

TEMPERATURE (°C)

4556 G02

Charge Pump Open-Loop Output Resistance vs Temperature (2V

– V

BATT

= 2.7V

BATT

= 4.9V

CPO

OUTPUT RESISTANCE (Ω)

–15 10 35 60 85

–40

) / I

CPO

TEMPERATURE (°C)

4556 G03

4556f

TEMPERATURE (°C)

–40

–15 10 35 60 85

I/O LOW OUTPUT VOLTAGE (mV)

4556 G06

200

175

150

125

100

DATA

= V

SYNC

= 0V

= –1mA

BATT

= 3V

VCC = 1.8V

VCC = 3V, 5V

DVCC

SUPPLY VOLTAGE (V)

2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5

SUPPLY CURRENT (µA)

4556 G09

1.0

0.8

0.6

0.4

0.2

TA = 25°C

TA = 85°C

TA = –40°C

BATT

= V

DVCC

TYPICAL PERFOR A CE CHARACTERISTICS

LTC4556

VCC Overcurrent Shutdown Threshold vs Temperature

140

= 3.3V

BATT

130

120

VCC = 5V, CPO = 5.5V

110

100

LOAD CURRENT (mA)

–15 10 35 60 85

–40

VCC = 1.8V, CPO = 4V

TEMPERATURE (°C)

Extra Input Current vs Load Current (I

= 3.3V

BATT

= 25°C

BATT

VCC = 3V, CPO = 5.5V

4556 G04

– 2ICC)

Card Detection Debounce Time vs V

Supply Voltage

BATT

DEBOUNCE TIME (ms)

2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 V

SUPPLY VOLTAGE (V)

BATT

Shutdown Current vs

BATT

TA = 85°C

TA = 25°C

TA = –40°C

Supply Voltage

3.0 V

= V

BATT

DVCC

2.5

2.0

1.5

TA = –40°C

TA = 25°C

Bidirectional Channel (I/O) Low Output Level vs Temperature

4556 G05

DVCC Shutdown Current vs Supply Voltage

EXTRA INPUT CURRENT (mA)

0.01 1 10

Charge Pump and LDO Activation Deactivation Sequence Data – I/O Channel

CPO

5V/DIV

I/O

0.1 100 LOAD CURRENT (mA)

1ms/DIV 4556 G10 10µs/DIV 4556 G11.eps

4556 G07

1.0

SUPPLY CURRENT (µA)

0.5

2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5

RST

5V/DIV

CLK

5V/DIV

I/O

5V/DIV

SUPPLY VOLTAGE (V)

BATT

TA = 85°C

4556 G08

I/O

2V/DIV

DATA

2V/DIV

100ns/DIV

4556 G12

4556f

LTC4556

UUU

PI FU CTIO S

DVCC (Pin 1): Power. Reference voltage for the control logic.

DATA (Pin 2): Input/Output. Microcontroller side data I/O pin. The DATA pin provides the bidirectional communication path to the smart card. The card may be selected to communicate via the DATA pin. If several LTC4556s are connected in parallel, the DATA pin can be made high impedance by selecting neither card socket. The C4 and C8 synchronous card pins can be selected to connect to the DATA pin via the serial port (see Table 4).

RIN (Pin 3): Input. The RIN pin supplies the RST signal to the smart card. It is level shifted and transmitted directly to the RST pin of a selected card. When the card is deselected, the RST pin is latched at its current state.

SYNC (Pin 4): Input-Input/Output. The SYNC pin provides the clock input for synchronous smart cards. When a synchronous card is selected, its CLK pin follows SYNC directly. When a synchronous card is deselected, the CLK pin is latched at its current state. In bidirectional mode, the SYNC pin becomes an input/output with the smart card CLK pin.

ASYNC (Pin 5): Input. The ASYNC pin provides the clock input for asynchronous cards and should be connected to a free running clock. The clock signal to the smart card can be a ÷1, ÷2, ÷4 or ÷8 version of the signal on ASYNC. Asynchronous cards can also be placed in clock stop mode with the clock stopped either high or low.

FAULT (Pin 6): Output. The FAULT pin can be used as an interrupt to a microcontroller to indicate when a fault has occurred. It is an open drain output, which is logically equivalent to D4 . (See Table 1)

NC (Pin 7): No Connection to chip. May be grounded. GND (Pin 8): Ground. Power ground for the chip. This pin

should be connected directly to a low impedance ground plane.

CPO (Pin 12): Charge Pump. CPO is the output of the charge pump. When the smart card requires power, the charge pump will charge CPO to either 3.7V or 5.35V depending on what smart card voltage is required. A low impedance 1µF X5R or X7R ceramic capacitor is required on CPO.

VCC (Pin 13): Card Socket. The V nected to the VCC pin of the smart card socket. The activation of the VCC pin is controlled by the serial port (see Tables 1 and 2) and can be set to 0V, 1.8V, 3V or 5V.

CLK (Pin 14): Card Socket. The CLK pin should be connected to the CLK pin of the smart card socket. The CLK signal can be derived from either the SYNC input or the ASYNC input depending on which type of card is being accessed. The card type is selected via the serial port (see Tables 1 and␣ 3). In bidirectional mode, the CLK pin becomes an input/output with the microcontroller side SYNC pin.

RST (Pin 15): Card Socket. This pin should be connected to the RST pin of the smart card socket. The RST signal is derived from the RIN pin. When the card is selected, its RST pin follows RIN. When the card is deselected, the RST pin holds the current value on RIN.

I/O (Pin 16): Card Socket. The I/O pin connects to the I/O pin of the smart card socket. When the smart card is selected, its I/O pin connects to the DATA pin. When the smart card is deselected, its I/O pin returns to the idle state (H).

C4, C8 (Pins 17, 18): Card Socket. These pins connect to the C4 and C8 pins of synchronous memory cards on the smart card socket. The signal for these pins is unidirectional and can only be sent to the card. Data for C4 and C8 is transmitted via the DATA pin and may be selected in place of I/O via the serial port (see Table 4). When either C4 or C8 is selected, it will follow the DATA pin. When it is deselected, it will remain latched at its current state.

pin should be con-

C–, C+ (Pins 9, 11): Charge Pump. Charge pump flying capacitor pins. A 1µF X5R or X7R ceramic capacitor should be connected from C+ to C–.

(Pin 10): Power. Supply voltage for analog and

BATT

power sections of the LTC4556.

PRES (Pin 19): Card Socket. The PRES pin is used to detect the presence of a smart card. It should be connected to a normally open detection switch on the smart card acceptor’s socket. This pin has a pull-up current source on-chip so no external components are required.

4556f

UUU

PI FU CTIO S

LTC4556

UNDERV (Pin 20): Input. The UNDERV pin provides security by supplying a precision undervoltage threshold for external supply monitoring. An external resistive voltage divider programs the desired undervoltage threshold. Once UNDERV falls below 1.23V, the LTC4556 automatically begins the deactivation sequence.

If external supply monitoring is not required, the UNDERV pin should be connected to either V

BATT

or DVCC.

DIN (Pin 21): Input. Input for the serial port. Command data is shifted into DIN synchronously with SCLK. DIN can be connected directly to a microcontroller or the D

OUT

pin of another LTC4556 or LTC1955 for daisy chained operation.

(Pin 22): Output. Output for the serial port. Smart

OUT

card status data is shifted out of D

synchronously with

OUT

BLOCK DIAGRA

CHARGE PUMP

–

C+C

11 9

CHARGE

PUMP

SCLK. D

can be connected directly to a microcontroller

OUT

or the DIN pin of another LTC4556 or LTC1955 for daisy chained operation.

SCLK (Pin 23): Input. The SCLK pin clocks the serial port. Each new data bit is received on the rising edge of SCLK. SCLK should be left high during idle times and should not be clocked when LD is low.

LD (Pin 24): Input. The falling edge of this pin loads the current state of the shift register into the command register. Command changes to the smart card will be updated on the falling edge of LD. The rising edge of LD latches status information into the shift register for the next read/ write cycle.

SGND (Pin 25): Exposed Pad. Must be soldered to PCB Ground.

GND

BATT

10 12

CPO

SMART

CARD

COMMUNICATIONS

SERIAL PORT

COMMAND/STATUS

DATA

ASYNC

SYNC

SCLK

OUT

1.23V

I/O

SMART

4556 BD

CLK

RST

PRES

FAULT

UNDERV

CARD SOCKET

DIGITAL SUPPLY

4556f

+ –

LDO

CLOCK

CONTROL

LOGIC

RESET

CONTROL

LOGIC

STATUS DATA

SHIFT REGISTER

COMMAND LATCH

–

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