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LTC4558 Dual SIM / Smart Card Power Supply and Interface FEATURES

, LT, LTC and L are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6356140.

LTC4558 Dual SIM / Smart Card Power Supply and Interface FEATURES
DESCRIPTION
, LT, LTC and L are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6356140.
APPLICATIONS
GSM, TD-SCDMA and other 3G+ Cellular Phones Wireless Point-of-Sale Terminals Multiple SIM Card Interfaces
TYPICAL APPLICATION
DVCC VBATT 1.4V TO 4.4V 3V TO 6V DVCC 0.1µF DVCC CLKIN RSTIN DATA CLKRUNA µCONTROLLER CLKRUNB GND ENABLEA ENABLEB CSEL VSELA VSELB LTC4558 VCCB CLKB RSTB I / OB 1µF C1 C3 C2 C7 VCC CLK RST I / O GND C5
4558 TA01
0.1µF VBATT I / OA RSTA CLKA VCCA 1µF C7 C2 C3 CLK C1 VCC I / O RST 1.8V / 3V SIM CARD A GND C5
Deactivation Sequence
4558 TA02
1.8V / 3V SIM CARD B
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LTC4558 ABSOLUTE MAXIMUM RATINGS
(Note 1)
PACKAGE / ORDER INFORMATION
TOP VIEW ENABLEB RSTIN VSELB 15 CLKRUNB 14 CLKRUNA 21 13 CSEL 12 VSELA 11 ENABLEA 6 RSTA 7 I / OA 8 DATA 9 10 CLKIN RSTB CLKB VCCB 1 DVCC 2 VBATT 3 VCCA 4 CLKA 5 I / OB
VBATT, DVCC, DATA, RSTIN, CLKIN, CLKRUNA, CLKRUNB, ENABLEA, ENABLEB, CSEL, VSELA, VSELB to GND ....................... -0.3V to 6V I / OA, CLKA, RSTA ............ -0.3V to VCCA + 0.3V I / OB, CLKB, RSTB ............ -0.3V to VCCB + 0.3V ICCA, B (Note 4) ............................80mA VCCA, B Short-Circuit Duration .............. Indefinite Operating Temperature Range (Note 3) ..-40°C to 85°C Storage Temperature Range..........-65°C to 125°C
ORDER PART NUMBER LTC4558EUD
UD PART MARKING LCSH
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com / leadfree / Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
MAX 5.5
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LTC4558 ELECTRICAL CHARACTERISTICS
MAX 0.2
UNITS V V
VCCA, B -0.2 16 10 0.2 VCCA, B -0.2 100 0.3 0.85 · VCCA, B 500 5 10 0.3 0.8 · DVCC 125 500 0.15 · DVCC 0.85 · DVCC -1 1
ENABLEA, ENABLEB, RSTIN, CLKIN, CSEL, VSELA, VSELB, CLKRUNA, CLKRUNB
Note 3: The LTC4558E is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the -40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 4: Based on long-term current density limitations.
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LTC4558 TYPICAL PERFORMANCE CHARACTERISTICS
No Load Supply Current vs VBATT
100 95 VBATT SUPPLY CURRENT (µA) 90 85 80 75 70 65 60 55 50 2.7 3.1 3.9 4.3 4.7 5.1 VBATT SUPPLY VOLTAGE (V) 3.5 5.5 4.0 -40 0 -15 35 10 TEMPERATURE (°C) 60 85
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I / OX Short-Circuit Current vs Temperature
DROPOUT
100 1000 10000 LOAD CURRENT (µA)
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4557 G01
VBATT Shutdown Current vs Supply Voltage
DVCC Shutdown Current vs Supply Voltage
1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5.6 DVCC SUPPLY VOLTAGE (V)
4557 G05
4557 G04
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LTC4558 TYPICAL PERFORMANCE CHARACTERISTICS
DATA 1V / DIV
200ns / DIV
4557 G06
RSTX 5V / DIV CLKX 5V / DIV I / OX 5V / DIV VCCX 2V / DIV 20µs / DIV
4557 G07
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LTC4558 PIN FUNCTIONS
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LTC4558 BLOCK DIAGRAM
DVCC 2 VBATT 3
VCCA 4
1 VCCB
RSTA 6
19 RSTB
CLKA 5
20 CLKB
CLKRUNA 14 DATA 8 RSTIN 9 CLKIN 10 DVCC
15 CLKRUNB
CONTROL LOGIC
21 GND
13 CSEL
17 ENABLEB
VSELA ENABLEA VSELB
4558 BD
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LTC4558 OPERATION
The LTC4558 features two independent SIM / Smart Card channels. Only one of these channels may be open for communication at a time however both channels can be enabled and made ready for communication using the ENABLEA and ENABLEB pins. This allows faster transition from one channel to the other. Each channel is able to produce two voltage levels, 1.8V and 3V. The channel selection and voltage selection are controlled by the CSEL, VSELA and VSELB pins as shown in the table below:
Table 1. Channel and Voltage Truth Table
CSEL 0 0 0 0 1 1 1 1 VSELA 0 0 1 1 0 0 1 1 VSELB 0 1 0 1 0 1 0 1 SELECTED CARD A A A A B B B B VOLTAGES A B 1.8V 1.8V 3V 3V 1.8V 1.8V 3V 3V 1.8V 3V 1.8V 3V 1.8V 3V 1.8V 3V
BIDIRECTIONAL PIN dv dt ISTART
Dynamic Pull-Up Current Sources The current sources on the bidirectional pins (DATA, I / OA, B) are dynamically activated to achieve a fast rise time with a relatively small static current. Once a bidirectional pin is relinquished, a small start-up current begins to charge the node. An edge rate detector determines if the pin is released by comparing its slew rate with an internal reference value. If a valid transition is detected, a large pull-up current enhances the edge rate on the node. The higher slew rate corroborates the decision to charge the node thereby affecting a dynamic form of hysteresis.
LOCAL SUPPLY
4558 F01
Figure 1. Dynamic Pull-Up Current Source
Bidirectional Channels The bidirectional channels are level shifted to the appropriate VCCA, B voltages at the I / OA, B pins. An NMOS pass transistor performs the level shifting. The gate of the NMOS transistor is biased such that the transistor is completely off when both sides have relinquished the channel. If one side of the channel asserts a LOW, then the transistor will convey the LOW to the other side. Note that current passes from the receiving side of the channel to the transmitting side. The low output voltage of the receiving side will be dependent upon the voltage at the transmitting side plus the IR drop of the pass transistor. When a card socket is selected, it becomes a candidate to drive data on the DATA pin and likewise receive data from the DATA pin. When a card socket is deselected, its I / O pin will be pulled HIGH and communication with the DATA pin will be disabled. If both channels are disabled, a weak pull-up ensures that the DATA pin is held HIGH, as long as DVCC is powered.
Reset Channels When a card is selected, the reset channel provides a level shifted path from the RSTIN pin to the RST pin of the selected card. When a card is deselected, the last state of the RSTA, B pin is latched. This allows a deselected card to remain active, and therefore eliminates delays associated with card initialization. Clock Run Mode Various SIM / Smart Cards may have different requirements for the state of the clock pin when the channel is not open for communication. The CLKRUNA, B pins allow the user to select whether the clock is brought LOW after the channel is deselected or allowed to run. If a channel is enabled, bringing its CLKRUN pin HIGH will transmit the clock to the corresponding card socket, whether or not the channel is selected using the CSEL.
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LTC4558 OPERATION
Activation / Deactivation Activation and deactivation sequencing is handled by builtin circuitry. Each channel may be activated or deactivated independently of the other. The activation sequence for each channel is initiated by bringing the ENABLEA, B pin HIGH. The activation sequence is outlined below: 1. The RSTA, B, CLKA, B and I / OA, B pins are held LOW. 2. VCCA, B is enabled. 3. After VCCA, B is stable at its selected level, the I / OA, B and RSTA, B channels are enabled. 4. The clock channel is enabled on the rising edge of the second clock cycle after the I / OA, B pin is enabled. The deactivation sequence is initiated by bringing the ENABLEA, B pin LOW. The deactivation sequence is outlined below: 1. The reset channel is disabled and RSTA, B is brought LOW. 2. The clock channel is disabled and the CLKA, B pin is brought LOW two clock cycles after ENABLEA, B is brought LOW. If the clock is not running, the clock channel will be disabled approximately 9µs after the ENABLEA, B pin is brought LOW. 3. The I / O channel is disabled and the I / OA, B pin is brought LOW approximately 9µs after the ENABLEA, B pin is brought LOW. 4. VCCA, B will be depowered after the I / OA, B pin is brought LOW. The activation or deactivation sequences will take place every time a card channel is enabled or disabled. When a channel is deselected using the CSEL pin, the RSTA, B state is latched, the I / OA, B channel becomes high impedance and CLKA, B is brought LOW after a maximum of two clock cycles. Fault Detection The VCCA, B, I / OA, B, RSTA, B, CLKA, B and DATA pins are all protected against short-circuit faults. While there are no logic outputs to indicate that a fault has occurred, these pins will be able to tolerate the fault condition until it has been removed. The VCCA, B, I / OA, B, and RSTA, B pins possess fault protection circuitry which will limit the current available to the pins. Each VCC pin is capable of supplying approximately 90mA (typ) before the output voltage is reduced. The CLKA, B pins are designed to tolerate faults by reducing the current drive capability of their output stages. After a fault is detected by the internal fault detection logic, the logic waits for a fault detection delay to elapse before reducing the current drive capability of the output stage. The reduced current drive allows the LTC4558 to detect when the fault has been removed.
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LTC4558 APPLICATIONS INFORMATION
10kV ESD Protection All Smart Card pins (CLKA, B, RSTA, B, I / OA, B, VCCA, B and GND) can withstand over 10kV of human body model ESD in-situ. In order to ensure proper ESD protection, careful board layout is required. The GND pin should be tied directly to a ground plane. The VCCA, B capacitors should be located very close to the VCCA, B pins and tied immediately to the ground plane. Capacitor Selection A total of four capacitors is required to operate the LTC4558. An input bypass capacitor is required at VBATT and DVCC. Output bypass capacitors are required on each of the Smart Card VCC pins. There are several types of ceramic capacitors available, each having considerably different characteristics. For example, X7R ceramic capacitors have excellent voltage and temperature stability but relatively low packing density. Y5V and X5R ceramic capacitors have apparently higher packing density but poor performance over their rated voltage or temperature ranges. Under certain voltage and temperature conditions Y5V, X5R and X7R ceramic capacitors can be compared directly by case size rather than specified value for a desired minimum capacitance. The VCCA, B outputs should be bypassed to GND with a 1µF capacitor. A low ESR ceramic capacitor is recommended on each VCC pin to ensure ESD compliance. VBATT and DVCC should be bypassed with 0.1µF ceramic capacitors. Compliance Testing Inductance due to long leads on type approval equipment can cause ringing and overshoot that leads to testing problems. Small amounts of capacitance and damping resistors can be included in the application without compromising the normal electrical performance of the LTC4558 or Smart Card system. Generally a 100 resistor and a 20pF capacitor will accomplish this, as shown in Figure 2.
1µF LTC4558 VCCA, B CLKA, B RSTA, B 100 I / OA, B 20pF
4558 F02
100 100 20pF 20pF
20pF SMART CARD SOCKET
Figure 2. Additional Components for Improved Compliance Testing
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LTC4558 PACKAGE DESCRIPTION
(UD20) QFN 0306 REV A
0.200 REF 0.00 - 0.05 NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE
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Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
LTC4558 TYPICAL APPLICATION
DVCC VBATT 1.4V TO 4.4V 3V TO 6V DVCC C3 0.1µF C4 0.1µF C7 C2 C3 CLK C1 C1 1µF GND ENABLEA ENABLEB CSEL VSELA VCCB CLKB RSTB C2 1µF C1 C3 C2 C7 VCC CLK RST I / O GND C5
4558 TA01a
DVCC CLKIN RSTIN DATA CLKRUNA
VBATT I / OA RSTA CLKA VCCA
I / O RST 1.8V / 3V SIM CARD A GND C5
µCONTROLLER
CLKRUNB
1.8V / 3V SIM CARD B
I / OB VSELB LTC4558
RELATED PARTS
LTC1955
LTC1986 LTC4555 LTC4556 LTC4557
ThinSOT is a trademark of Linear Technology Corporation.
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12 Linear Technology Corporation
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