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LTC1555/LTC1556 SIM Power Supply and Level Translator
FEATURES
s s s
DESCRIPTION
The LTC(R)1555/LTC1556 provide power conversion and level shifting needed for 3V GSM cellular telephones to interface with either 3V or 5V Subscriber Identity Modules (SIMs). These parts contain a charge pump DC/DC converter that delivers a regulated 5V to the SIM card. Input voltage may range from 2.7V to 10V, allowing direct connection to the battery. Output voltage may be programmed to 3V, 5V or direct connection to the VIN pin. A soft start feature limits inrush current at turn-on, mitigating start-up problems that may result when the input is supplied by another low power DC/DC converter. The LTC1556 also includes an auxiliary LDO regulator/ power switch that may be used to power the frequency synthesizer or other low power circuitry. Battery life is maximized by 60A operating current and 1A shutdown current. Board area is minimized by miniature 16- and 20-pin narrow SSOP packages and the need for only three small external capacitors.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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Step-Up/Step-Down Charge Pump Generates 5V Input Voltage Range: 2.7V to 10V Output Current: 10mA (VIN 2.7V) 20mA (VIN 3V) 3V to 5V Signal Level Translators > 10kV ESD on All SIM Contact Pins Short-Circuit and Overtemperature Protected Very Low Operating Current: 60A Very Low Shutdown Current: < 1A Soft Start Limits Inrush Current at Turn-On Programmable 3V or 5V Output Voltage 650kHz Switching Frequency Auxiliary 4.3V LDO/Power Switch (LTC1556 Only) Available in a 16- and 20-Pin Narrow SSOP
APPLICATIONS
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SIM Interface in GSM Cellular Telephones Smart Card Readers
TYPICAL APPLICATION
GSM Cellular Telephone SIM Interface
3V GSM CONTROLLER
3V 1 2 3 4
LTC1555 CIN RIN DATA DDRV DVCC SS M1 M0 CLK RST I/O VCC VIN C1 + 16 15 14 13 12 11
VIN 2.7V TO 10V CLK RST I/O
VCC
5 6 7 8
+
0.1F 10F
10 C1 - 9 GND
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SIM
10F
VCC 5V 5% IVCC 10mA
GND
1555/56 TA01
1
LTC1555/LTC1556
ABSOLUTE MAXIMUM RATINGS
(Note 1)
VIN, DVCC to GND ..................................... - 0.3V to 12V VCC to GND ............................................... - 0.3V to 12V Digital Inputs to GND ................................ - 0.3V to 12V LDO, CLK, RST, I/O to GND ........ - 0.3V to (VCC + 0.3V) VCC, LDO Short-Circuit Duration ..................... Indefinite Storage Temperature Range ................. - 65C to 150C
PACKAGE/ORDER INFORMATION
TOP VIEW CIN RIN DATA DDRV DVCC SS M1 M0 1 2 3 4 5 6 7 8 16 CLK 15 RST 14 I/O 13 VCC 12 VIN 11 C1 + 10 C1 - 9 GND
ORDER PART NUMBER LTC1555CGN LTC1555IGN
GN PACKAGE 16-LEAD PLASTIC SSOP
TJMAX = 150C, JA = 135C/ W
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
VIN = 2.7V to 10V, DVCC = 1.8V to 5.5V, controller digital pins tied to DVCC, SIM digital pins floating, EN, FB pins tied to GND (LTC1556), C1 = 0.1F, COUT = 10F unless otherwise specified.
PARAMETER VIN Operating Voltage DVCC Operating Voltage VIN Operating Current VIN Shutdown Current 2.7V VIN 5V, VCC = 5V, IVCC = 0 5V < VIN 10V, VCC = 5V, IVCC = 0 M0, M1 = 0V, 2.7V VIN 5V M0, M1 = 0V, 2.7V VIN 5V M0, M1 = 0V, 5V < VIN 10V M0, M1 = DVCC, CIN = 1MHz M0, M1 = 0V 0 IVCC 10mA, 2.7V VIN 10V 0 IVCC 20mA, 3V VIN 10V M0, M1 = DVCC M0 = DVCC, M1 = 0 M0 = 0, M1 = DVCC VIN = 3.6V, IVCC = 10mA, VCC = 5V CONDITIONS
q q q q q q q
DVCC Operating Current DVCC Shutdown Current VCC Output Voltage
VCC Output Ripple
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Temperature Range LTC1555C/LTC1556C .............................. 0C to 70C LTC1555I/LTC1556I ........................... - 40C to 85C Extended Commercial Operating Temperature Range (Note 2) ............................................. - 40C to 85C Lead Temperature (Soldering, 10 sec).................. 300C
TOP VIEW CIN RIN DATA DDRV EN FB DVCC SS M1 1 2 3 4 5 6 7 8 9 20 CLK 19 RST 18 I/O 17 LDO 16 VCC 15 VIN 14 C1 + 13 C1 - 12 GND 11 GND
ORDER PART NUMBER LTC1556CGN LTC1556IGN
M0 10
GN PACKAGE 20-LEAD PLASTIC SSOP TJMAX = 150C, JA = 95C/ W
MIN 2.7 1.8
TYP
MAX 10 5.5
UNITS V V A A A A A A A
60 75
100 135 1 2 25
6
20 1
q q q
4.75 2.80 VIN - 0.3
5.00 3.00 75
5.25 3.20 VIN
V V V mVP-P
LTC1555/LTC1556
ELECTRICAL CHARACTERISTICS
VIN = 2.7V to 10V, DVCC = 1.8V to 5.5V, controller digital pins tied to DVCC, SIM digital pins floating, EN, FB pins tied to GND (LTC1556), C1 = 0.1F, COUT = 10F unless otherwise specified.
PARAMETER VCC Short-Circuit Current Auxiliary LDO VOUT (VLDO) Auxiliary Switch Resistance FB Input Resistance Charge Pump fOSC Controller Inputs/Outputs, DVCC = 3V Input Current (IIH, IIL) High Level Input Current (IIH) Low Level Input Current (IIL) High Input Voltage Threshold (VIH) Low Input Voltage Threshold (VIL) High Level Output Voltage (VOH) Low Level Output Voltage (VOL) DATA Pull-up Resistance DATA Output Rise/Fall Time I/O High Input Voltage Threshold (VIH) I/O Low Input Voltage Threshold (VIL) High Level Output Voltage (VOH) Low Level Output Voltage (VOL) I/O Pull-Up Resistance CLK Rise/Fall Time RST, I/O Rise/Fall Time CLK Frequency VCC Turn-On Time VCC Discharge Time to 1V M0, M1, SS, RIN, CIN DDRV, EN DATA DATA M0, M1, RIN, CIN, DDRV, EN DATA M0, M1, RIN, CIN, DDRV, EN DATA DATA Source Current = 20A, I/O = VCC DATA Sink Current = - 200A, I/O = 0V (Note 3) Between DATA and DVCC DATA Loaded with 30pF IIH(MAX) = 20A IIL(MAX) = 1mA I/O, Source Current = 20A, DATA or DDRV = DVCC RST, CLK, Source Current = 20A I/O, Sink Current = - 1mA, DATA or DDRV = 0V (Note 3) RST, CLK, Sink Current = - 200A Between I/O and VCC CLK Loaded with 30pF RST, I/O Loaded with 30pF CLK Loaded with 30pF SS = DVCC, COUT = 10F, IVCC = 0 SS = 0V, COUT = 10F, IVCC = 0 IVCC = 0, VCC = 5V, COUT = 10F
q q q q q q q q q q q q
CONDITIONS VCC Shorted to GND EN = High, VCC = 5V, FB = LDO, ILDO = 5mA (LTC1556) EN = High, VCC = 5V, FB = GND (LTC1556) (LTC1556)
q q q q
MIN 4.00
TYP 12.5 4.3 18 200
MAX 40 4.55 30 800 1 5 20 1 0.7 x DVCC DVCC - 0.6
UNITS mA V k kHz A A A mA V V V V V
500 -1 -5 - 20
650
0.2 x DVCC 0.4 0.7 x DVCC 0.4 13 20 1.3 0.5 x VCC 0.4 0.8 x VCC 0.9 x VCC 0.4 0.4 6.5 10 14 18 1 5 1 6 3 28 2 0.7 x VCC
V k s V V V V V V k ns s MHz ms ms ms
SIM Inputs/Outputs, DVCC = 3V, VCC = 3V or 5V
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SIM Timing Parameters, DVCC = 3V, VCC = 5V
q q q
The q denotes specifications which apply over the specified temperature range. Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: C grade device specifications are guaranteed over the 0C to 70C temperature range. In addition, C grade device specifications are assured
over the - 40C to 85C temperature range by design or correlation, but are not production tested. Note 3: The DATA and I/O pull-down drivers must also sink current sourced by the internal pull-up resistors.
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LTC1555/LTC1556 TYPICAL PERFORMANCE CHARACTERISTICS
Operating Current vs Input Voltage
120 NO EXTERNAL LOAD
OPERATING CURRENT (A) SHUTDOWN CURRENT (A)
100 85C 80 25C
VCC OUTPUT VOLTAGE (V)
60
40
2
6 8 4 VIN INPUT VOLTAGE (V)
VCC Output Voltage vs Input Voltage (3V Mode)
3.2 IVCC = 10mA M0 = DVCC M1 = 0V COUT = 10F TA = 25C
VCC OUTPUT VOLTAGE (V)
3.1
1V/DIV
3.0
2.9
VIN = 3V SS = 0V
2.8 2 6 8 4 VIN INPUT VOLTAGE (V) 10
1555/56 G04
1ms/DIV
1555/56 G05
1V/DIV
3V VCC Efficiency vs Input Voltage
100 VCC = 3V IVCC = 10mA TA = 25C 80 80
EFFICIENCY (%)
EFFICIENCY (%)
60
40
20
0
2
4
UW
- 40C 10
1555/56 G01
Shutdown Current vs Input Voltage
20
VCC Output Voltage vs Input Voltage (5V Mode)
5.2 IVCC = 10mA M0 = DVCC M1 = DVCC COUT = 10F TA = 25C
15
5.1
10 85C 5 25C
5.0
4.9
- 40C 0 2 6 8 4 VIN INPUT VOLTAGE (V)
4.8
10
1555/56 G02
2
6 8 4 VIN INPUT VOLTAGE (V)
10
1555/56 G03
VCC Output Voltage Turn-On Time, SS Enabled
VCC Output Voltage Turn-On Time, SS Disabled
VIN = 3V SS = DVCC
1ms/DIV
1555/56 G06
5V VCC Efficiency vs Input Voltage
100 VCC = 5V IVCC = 10mA TA = 25C
60
40
20 6 8 4 VIN INPUT VOLTAGE (V) 10
1555/56 G07
2
4
8 10 6 VIN INPUT VOLTAGE (V)
12
1555/56 G08
LTC1555/LTC1556
PIN FUNCTIONS
LTC1555/LTC1556 CIN (Pin 1): Clock Input Pin from Controller. RIN (Pin 2): Reset Input Pin from Controller. DATA (Pin 3): Controller Side Data Input/Output Pin. Can be used for single pin bidirectional data transfer between the controller and the SIM card as long as the controller data pin is open drain. The controller output must be able to sink 1mA max when driving the DATA pin low due to the internal pull-up resistors on the DATA and I/O pins. If the controller data output is not open drain, then the DDRV pin should be used for sending data to the SIM card and the DATA pin used for receiving data from the SIM card (see Figure 1). DDRV (Pin 4): Optional Data Input Pin for Sending Data to the SIM card. When not needed, the DDRV pin should be left floating or tied to DVCC (an internal 1A current source will pull the DDRV pin up to DVCC if left floating). DVCC (Pins 5/7): Supply Voltage for Controller Side Digital I/O Pins. May be between 1.8V and 5.5V (typically 3V). SS (Pins 6/8): Soft Start Enable Pin. A logic low will enable the charge pump inrush current limiting feature. A logic high will disable the soft start feature and allow VCC to be ramped as quickly as possible upon start-up and coming out of shutdown. M1 (Pins 7/9): Mode Control Bit 1 (see Truth Table). M0 (Pins 8/10): Mode Control Bit 0 (see Truth Table). This table defines the various operating modes that may be obtained via the M0 and M1 mode control pins.
Truth Table
M0 0V 0V DVCC DVCC M1 0V DVCC 0V DVCC MODE Shutdown (VCC = 0V) VCC = VIN VCC = 3V VCC = 5V
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GND (Pins 9/11, 12): 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 10kV ESD specifications. C1- (Pins 10/12): Charge Pump Flying Capacitor Negative Input. C1+ (Pins 11/13): Charge Pump Flying Capacitor Positive Input. VIN (Pins 12/14): Charge Pump Input Voltage Pin. Input voltage range is 2.7V to 10V. Connect a 10F low ESR input bypass capacitor close to the VIN pin. VCC (Pins 13/15): SIM Card VCC Output. This pin should be connected to the SIM VCC contact. The VCC output voltage is determined by the M0 and M1 pins (see Truth Table). VCC is discharged to GND during shutdown (M0, M1 = 0V). A 10F low ESR output capacitor should connect close to the VCC pin. I/O (Pins 14/18): 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 when the part is in shutdown. RST (Pins 15/19): Level Shifted Reset Output Pin. Should be connected to the SIM RST contact. CLK (Pins 16/20): 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.
5
LTC1555/LTC1556
PIN FUNCTIONS
LTC1556 Only EN (Pin 5): Auxiliary LDO/Power Switch Enable Pin. A logic high on this pin from the controller will enable the auxiliary LDO output. When the LDO is disabled, the LDO output will float or be pulled to ground by the load. If left floating, the EN pin will be pulled down to GND by an internal 1A current source. FB (Pin 6): Auxiliary LDO Feedback Pin. When FB is connected to the LDO pin (Pin 17), the LDO output is regulated to 4.3V (typ). If the FB pin is left open or tied to ground, the regulator acts as a 30 switch between VCC and LDO. LDO (Pin 17): LDO Output Pin. This pin should be tied to the FB pin for 4.3V LDO operation. The 4.3V LDO output is usable only when VCC is 5V (or greater). It is not available when VCC = 3V. The LDO output may also be used as a 30 power switch if the FB pin is grounded or left floating. When used as a regulator, LDO must be bypassed to GND with a 3.3F capacitor. The LDO output current will subtract from available VCC current.
BLOCK DIAGRAM
VCC
CONTROLLER CIN 20k DATA 1A OPTIONAL DDRV GND EN 1A 1.23V FB 153k 61k LTC1555/LTC1556 LTC1556 ONLY
1555/56 BD
6
+
-
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VBATT
+
0.1F CIN 10F
C1+ VIN M1 M0 STEP-UP/ STEP-DOWN CHARGE PUMP DC/DC CONVERTER
C1- VCC COUT 10F
VCC
3V
SS
DVCC RIN RST RST SIM CLK 10k I/O I/O CLK
GND
GND FREQUENCY SYNTHESIZER POWER
LDO
4.3V
+
CLDO 10F
LTC1555/LTC1556
APPLICATIONS INFORMATION
The LTC1555/LTC1556 perform the two primary functions necessary for 3V controllers (e.g., GSM cellular telephone controllers, smart card readers, etc.) to communicate with 5V SIMs or smart cards. They produce a regulated 5V VCC supply for the SIM and provide level translators for communication between the SIM and the controller. VCC Voltage Regulator The regulator section of the LTC1555/LTC1556 (refer to the Block Diagram) consists of a step-up/step-down charge pump DC/DC converter. The charge pump can operate over a wide input voltage range (2.7V to 10V) while maintaining a regulated VCC output. The wide VIN range enables the parts to be powered directly from a battery (if desired) rather than from a 3V DC/DC converter output. When VIN is less than the desired VCC the parts operate as switched capacitor voltage doublers. When VIN is greater than VCC the parts operate as gated switch step-down converters. In either case, voltage conversion requires only one small flying capacitor and output capacitor. The VCC output can be programmed to either 5V or 3V via the M0 and M1 mode pins. This feature is useful in applications where either a 5V or 3V SIM may be used. The charge pump VCC output may also be connected directly to VIN if desired. When the charge pump is put into shutdown (M0, M1 = 0), VCC is pulled to GND via an internal switch to aid in proper system supply sequencing. The soft start feature limits inrush currents upon start-up or coming out of shutdown mode. When the SS pin is tied to GND, the soft start feature is enabled. This limits the effective inrush current out of VIN to approximately 25mA (COUT = 10F). Inrush current limiting is especially useful when powering the LTC1555/LTC1556 from a 3V DC/DC output since the unlimited inrush current may approach 200mA and cause voltage transients on the 3V supply. However, in cases where fast turn-on time is desired, the soft start feature may be overridden by tying the SS pin to DVCC. Capacitor Selection For best performance, it is recommended that low ESR (< 0.5) capacitors be used for both CIN and COUT to reduce noise and ripple. The CIN and COUT capacitors should be either ceramic or tantalum and should be 10F or greater (ceramic capacitors will produce the smallest output ripple). If the input source impedance is very low (< 0.5), CIN may not be needed. Increasing the size of COUT to 22F or greater will reduce output voltage ripple--particularly with high VIN voltages (8V or greater). A ceramic capacitor is recommended for the flying capacitor C1 with a value of 0.1F or 0.22F. Output Ripple Normal LTC1555/LTC1556 operation produces voltage ripple on the VCC pin. Output voltage ripple is required for the parts to regulate. Low frequency ripple exists due to the hysteresis in the sense comparator and propagation delays in the charge pump enable/disable circuits. High frequency ripple is also present mainly from the ESR (equivalent series resistance) in the output capacitor. Typical output ripple (VIN < 8V) under maximum load is 75mV peak-to-peak with a low ESR, 10F output capacitor. For applications requiring VIN to exceed 8V, a 22F or larger COUT capacitor is recommended to maintain maximum ripple in the 75mV range. The magnitude of the ripple voltage depends on several factors. High input voltages increase the output ripple since more charge is delivered to COUT per charging cycle. A large C1 flying capacitor (> 0.22F) also increases ripple in step-up mode for the same reason. Large output current load and/or a small output capacitor (< 10F) results in higher ripple due to higher output voltage dV/dt. High ESR capacitors (ESR > 0.5) on the output pin cause high frequency voltage spikes on VOUT with every clock cycle. A 10F ceramic capacitor on the VCC pin should produce acceptable levels of output voltage ripple in nearly all applications. However, there are several ways to further
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LTC1555/LTC1556
APPLICATIONS INFORMATION
reduce the ripple. A larger COUT capacitor (22F or greater) will reduce both the low and high frequency ripple due to the lower COUT charging and discharging dV/dt and the lower ESR typically found with higher value (larger case size) capacitors. A low ESR ceramic output capacitor will minimize the high frequency ripple, but will not reduce the low frequency ripple unless a high capacitance value is chosen (10F or greater). A reasonable compromise is to use a 10F to 22F tantalum capacitor in parallel with a 1F to 3.3F ceramic capacitor on VOUT to reduce both the low and high frequency ripple. An RC filter may also be used to reduce high frequency voltage spikes (see Figure 1).
VCC SIM VCC
+
15F TANTALUM
1F CERAMIC
LTC1555/ LTC1556 VCC 2 10F 10F
LT1555/56 F01
SIM VCC
Figure 1. VCC Output Ripple Reduction Techniques
Shutting Down the DVCC Supply To conserve power, the DVCC supply may be shut down while the VIN supply is still active. When the DVCC supply is brought to 0V, weak internal currents will force the LTC1555/LTC1556 into shutdown mode regardless of the voltages present on the M0 and M1 pins. However, if the M0 and M1 pins are floating or left connected to DVCC as the supply is shut down, the parts may take several
DVCC M0 0V DVCC M1 0V DVCC DVCC 0V VCC VCC 0V
1555/56 F02
Figure 2. Recommended DVCC Shutdown and Start-Up Timing
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hundred milliseconds to completely shut down. To ensure prompt and proper VCC shutdown, always force the M0 and M1 pins to a logic low state before shutting down the DVCC supply (see Figure 2). Similarly, bring the DVCC supply to a valid level before allowing the M0 and M1 pins to go high when coming out of shutdown. This can be achieved with pull-down resistors from M0 and M1 to GND if necessary. (Note: shutting down the DVCC supply with VIN active is not recommended with early date code material. Consult factory for valid date code starting point for shutting down the DVCC supply.) Level Translators All SIMs and smart cards contain a clock input, reset input and a bidirectional data input/output. The LTC1555/ LTC1556 provide level translators to allow controllers to communicate with the SIM (see Figures 3a and 3b). The CLK and RST inputs to the SIM are level shifted from the controller supply rails (DVCC and GND) to the SIM supply rails (VCC and GND). The data input to the SIM may be provided two different ways. The first method is to use the DATA pin as a bidirectional level translator. This configuration is only allowed if the controller data output pin is open drain (all SIM I/O pins are open drain). Internal pullup resistors are provided for both the DATA pin and the
LTC1555/LTC1556 CLK TO SIM RST TO SIM DATA TO/FROM SIM CIN RIN DATA DDRV CONTROLLER SIDE DVCC CLK RST I/O VCC SIM SIDE
1555/56 F3a
Figure 3a. Level Translator Connections for Bidirectional Controller DATA Pin
LTC1555/LTC1556 CLK TO SIM RST TO SIM DATA FROM SIM DATA TO SIM CONTROLLER SIDE CIN RIN DATA DDRV DVCC CLK RST I/O VCC SIM SIDE
1555/56 F3b
Figure 3b. Level Translator Connections for One-Directional Controller Side DATA Flow
LTC1555/LTC1556
APPLICATIONS INFORMATION
I/O pin on the SIM side. The second method is to use the DDRV pin to send data to the SIM and use the DATA pin to receive data from the SIM. When the DDRV pin is not used, it should either be left floating or tied to DVCC. Level Translation with DVCC > VCC It is assumed that most applications for these parts will use controller supply voltages (DVCC) less than or equal to VCC. In cases where DVCC is greater than VCC by more than 0.6V or so, the parts' operation will be affected in the following ways: 1) A small DC current (up to 100A) will flow from DVCC to VCC through the DATA pull-up resistor, N-channel pass device and the I/O pull-up resistor (except when the part is in shutdown at which time DVCC is disconnected from VCC by turning off the pass device). If the VCC load current is less than the DVCC current, the VCC output may be pulled out of regulation until sufficient load current pulls VCC back into regulation. 2) When the SIM is sending data back to the controller, a logic high on the I/O pin will result in the DATA pin being pulled up to [VCC + 1/3(DVCC - VCC)], not all the way up to DVCC. For example, if DVCC is 5V and VCC is 3V, the DATA pin will only swing from 0.1V to 3.67V when receiving data from the SIM side. Optional LDO Output The LTC1556 also contains an internal LDO regulator for providing a low noise boosted supply voltage for low power external circuitry (e.g., frequency synthesizers, etc.) Tying the FB pin to the LDO pin provides a regulated 4.3V at the LDO output (see Figure 4). A 3.3F (minimum) capacitor is required to ensure output stability. A 10F low ESR capacitor is recommended, however, to minimize LDO output noise. The LDO output may also be used as an auxiliary switch to VCC. If the FB pin is left floating or is tied to GND, the LDO pin will be internally connected to the VCC output through the P-channel pass device. The LDO may be disabled at any time by switching the EN pin from DVCC to GND. The 4.3V LDO output is usable only when VCC is 5V (or greater). It is not available when VCC = 3V.
EN OFF ON 1A VCC = 5V VREF FB 153k 61k
Figure 4. Auxiliary LDO Connections (LTC1556 Only)
10kV ESD Protection All pins that connect to the SIM (CLK, RST, I/O, VCC, GND) withstand over 10kV of human body model (100pF/1.5k) ESD. In order to ensure proper ESD protection, careful board layout is required. The GND pins should be tied directly to a GND plane. The VCC capacitor should be located very close to the VCC pin and tied immediately to the GND plane.
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LDO
4.3V
+
1555/56 F04
ILDO 0mA to 10mA 10F TANT
9
LTC1555/LTC1556
PACKAGE DESCRIPTION
0.007 - 0.0098 (0.178 - 0.249) 0.016 - 0.050 (0.406 - 1.270)
* DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
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Dimensions in inches (millimeters) unless otherwise noted.
GN Package 16-Lead Plastic SSOP (Narrow 0.150)
(LTC DWG # 05-08-1641)
0.189 - 0.196* (4.801 - 4.978) 16 15 14 13 12 11 10 9
0.229 - 0.244 (5.817 - 6.198)
0.150 - 0.157** (3.810 - 3.988)
1 0.015 0.004 x 45 (0.38 0.10) 0 - 8 TYP 0.053 - 0.068 (1.351 - 1.727)
23
4
56
7
8 0.004 - 0.0098 (0.102 - 0.249)
0.008 - 0.012 (0.203 - 0.305)
0.025 (0.635) BSC
GN16 (SSOP) 1197
LTC1555/LTC1556
PACKAGE DESCRIPTION
0.007 - 0.0098 (0.178 - 0.249) 0.016 - 0.050 (0.406 - 1.270)
* DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
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.
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Dimensions in inches (millimeters) unless otherwise noted.
GN Package 20-Lead Plastic SSOP (Narrow 0.150)
(LTC DWG # 05-08-1641)
0.337 - 0.344* (8.560 - 8.737) 20 19 18 17 16 15 14 13 12 11
0.229 - 0.244 (5.817 - 6.198)
0.150 - 0.157** (3.810 - 3.988)
1 0.015 0.004 x 45 (0.38 0.10) 0 - 8 TYP 0.053 - 0.068 (1.351 - 1.727)
23
4
56
7
8
9 10 0.004 - 0.0098 (0.102 - 0.249)
0.008 - 0.012 (0.203 - 0.305)
0.025 (0.635) BSC
GN20 (SSOP) 1197
11
LTC1555/LTC1556
TYPICAL APPLICATION
SIM Interface with Auxilary Power
4.3V 50mA AUXILIARY LDO/POWER SWITCH (FREQUENCY SYNTHESIZER) SIM CLK RST I/O
3V GSM CONTROLLER
3V 1 2 3 4 5 6
VCC
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PART NUMBER
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DESCRIPTION
Regulated Step-Up/Step-Down Charge Pumps with Reset Output Micropower, Regulated 5V Charge Pump DC/DC Converter Micropower, Regulated 5V Charge Pump DC/DC Converter Micropower, Regulated 5V Charge Pump DC/DC Converter Low Noise, Charge Pump Voltage Inverter 100mA Charge Pump DC/DC Converter
Regulated Step-Up/Step-Down Charge Pumps with Low Bat Comparator 3.3V and 5V Output Versions Adjustable, 3V/5V, 3.3V/5V Versions IOUT = 20mA (VIN 2V), IOUT = 50mA (VIN 3V) LTC1522 Without Shutdown and Packaged in SOT-23 IOUT = 20mA (VIN 3V), IQ = 6A 1mVP-P Ripple at 900kHz 5V to - 5V at 100mA
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417 q (408) 432-1900 FAX: (408) 434-0507q TELEX: 499-3977 q www.linear-tech.com
U
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10F LTC1556 CIN RIN DATA DDRV EN FB DVCC SS M1 M0 CLK RST I/O LDO VCC VIN C1 + C1 - GND GND 20 19 18 17 16 15 14 13 12 11 0.1F 10F VIN 2.7V TO 10V
7 8 9 10
VCC 5V 5% IVCC 10mA
+
10F GND
1555/56 TA02
COMMENTS
15556f LT/TP 0398 4K * PRINTED IN USA
(c) LINEAR TECHNOLOGY CORPORATION 1997

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