LTC1555/LTC1556 SIM Power Supply and Level Translator U DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ The LTC®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. 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: 60µA Very Low Shutdown Current: < 1µA 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 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. U APPLICATIONS ■ ■ Battery life is maximized by 60µA operating current and 1µA shutdown current. Board area is minimized by miniature 16- and 20-pin narrow SSOP packages and the need for only three small external capacitors. SIM Interface in GSM Cellular Telephones Smart Card Readers , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATION GSM Cellular Telephone SIM Interface 3V GSM CONTROLLER 3V 1 2 3 4 VCC VIN 2.7V TO 10V LTC1555 5 6 7 8 CIN CLK RIN RST DATA I/O DDRV VCC DVCC VIN SS C1 + M1 M0 SIM 16 CLK 15 RST 14 I/O 13 12 11 10 C1 – 9 GND 10µF + 0.1µF VCC 5V ± 5% IVCC ≤ 10mA 10µF GND 1555/56 TA01 1 LTC1555/LTC1556 U W W W 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 ................. – 65°C to 150°C Temperature Range LTC1555C/LTC1556C .............................. 0°C to 70°C LTC1555I/LTC1556I ........................... – 40°C to 85°C Extended Commercial Operating Temperature Range (Note 2) ............................................. – 40°C to 85°C Lead Temperature (Soldering, 10 sec).................. 300°C U W U PACKAGE/ORDER INFORMATION ORDER PART NUMBER TOP VIEW CIN 1 16 CLK RIN 2 15 RST DATA 3 14 I/O LTC1555CGN LTC1555IGN CIN 1 20 CLK RIN 2 19 RST DATA 3 18 I/O DDRV 4 17 LDO EN 5 16 VCC DDRV 4 13 VCC DVCC 5 12 VIN FB 6 15 VIN SS 6 11 C1 + DVCC 7 14 C1 + M1 7 10 C1 – SS 8 13 C1 – M0 8 9 GND M1 9 12 GND M0 10 11 GND GN PACKAGE 16-LEAD PLASTIC SSOP ORDER PART NUMBER TOP VIEW LTC1556CGN LTC1556IGN GN PACKAGE 20-LEAD PLASTIC SSOP TJMAX = 150°C, θJA = 95°C/ W TJMAX = 150°C, θJA = 135°C/ 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 = 0.1µF, COUT = 10µF unless otherwise specified. PARAMETER CONDITIONS MIN TYP MAX UNITS VIN Operating Voltage ● 2.7 10 V DVCC Operating Voltage ● 1.8 5.5 V 100 135 µA µA 1 2 25 µA µA µA 20 µA 1 µA 5.25 3.20 VIN V V V VIN Operating Current 2.7V ≤ VIN ≤ 5V, VCC = 5V, IVCC = 0 5V < VIN ≤ 10V, VCC = 5V, IVCC = 0 ● ● VIN Shutdown Current M0, M1 = 0V, 2.7V ≤ VIN ≤ 5V M0, M1 = 0V, 2.7V ≤ VIN ≤ 5V M0, M1 = 0V, 5V < VIN ≤ 10V ● DVCC Operating Current M0, M1 = DVCC, CIN = 1MHz ● DVCC Shutdown Current M0, M1 = 0V ● VCC Output Voltage 0 ≤ IVCC ≤ 10mA, 2.7V ≤ VIN ≤ 10V 0 ≤ IVCC ≤ 20mA, 3V ≤ VIN ≤ 10V M0, M1 = DVCC M0 = DVCC, M1 = 0 M0 = 0, M1 = DVCC ● ● ● VCC Output Ripple 2 VIN = 3.6V, IVCC = 10mA, VCC = 5V 60 75 6 4.75 2.80 VIN – 0.3 5.00 3.00 75 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 = 0.1µF, COUT = 10µF unless otherwise specified. PARAMETER CONDITIONS VCC Short-Circuit Current VCC Shorted to GND ● MIN Auxiliary LDO VOUT (VLDO) EN = High, VCC = 5V, FB = LDO, ILDO = 5mA (LTC1556) ● Auxiliary Switch Resistance EN = High, VCC = 5V, FB = GND (LTC1556) ● FB Input Resistance (LTC1556) 4.00 TYP MAX 12.5 40 4.3 4.55 18 30 UNITS mA V Ω 200 Charge Pump fOSC ● 500 650 kΩ 800 kHz µA µA Controller Inputs/Outputs, DVCC = 3V Input Current (IIH, IIL) M0, M1, SS, RIN, CIN DDRV, EN ● ● –1 –5 1 5 High Level Input Current (IIH) DATA ● – 20 20 µA Low Level Input Current (IIL) DATA ● 1 mA High Input Voltage Threshold (VIH) M0, M1, RIN, CIN, DDRV, EN DATA ● ● 0.7 × DVCC DVCC – 0.6 Low Input Voltage Threshold (VIL) M0, M1, RIN, CIN, DDRV, EN DATA ● ● 0.2 × DVCC 0.4 High Level Output Voltage (VOH) DATA Source Current = 20µA, I/O = VCC ● 0.7 × DVCC Low Level Output Voltage (VOL) DATA Sink Current = – 200µA, I/O = 0V (Note 3) ● DATA Pull-up Resistance Between DATA and DVCC ● DATA Output Rise/Fall Time DATA Loaded with 30pF V V V V V 0.4 V 20 28 kΩ ● 1.3 2 µs IIH(MAX) = ±20µA ● 0.5 × VCC 0.7 × VCC V I/O Low Input Voltage Threshold (VIL) IIL(MAX) = 1mA ● 0.4 V High Level Output Voltage (VOH) I/O, Source Current = 20µA, DATA or DDRV = DVCC RST, CLK, Source Current = 20µA ● ● 0.8 × VCC 0.9 × VCC V V Low Level Output Voltage (VOL) I/O, Sink Current = – 1mA, DATA or DDRV = 0V (Note 3) RST, CLK, Sink Current = – 200µA ● ● I/O Pull-Up Resistance Between I/O and VCC ● 13 SIM Inputs/Outputs, DVCC = 3V, VCC = 3V or 5V I/O High Input Voltage Threshold (VIH) 6.5 10 0.4 0.4 V V 14 kΩ SIM Timing Parameters, DVCC = 3V, VCC = 5V CLK Rise/Fall Time CLK Loaded with 30pF ● 18 ns RST, I/O Rise/Fall Time RST, I/O Loaded with 30pF ● 1 µs CLK Frequency CLK Loaded with 30pF ● 5 MHz VCC Turn-On Time SS = DVCC, COUT = 10µF, IVCC = 0 SS = 0V, COUT = 10µF, IVCC = 0 1 6 ms ms VCC Discharge Time to 1V IVCC = 0, VCC = 5V, COUT = 10µF 3 ms The ● 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 0°C to 70°C temperature range. In addition, C grade device specifications are assured over the – 40°C to 85°C 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. 3 LTC1555/LTC1556 U W TYPICAL PERFORMANCE CHARACTERISTICS Operating Current vs Input Voltage Shutdown Current vs Input Voltage 120 VCC Output Voltage vs Input Voltage (5V Mode) 5.2 20 IVCC = 10mA M0 = DVCC M1 = DVCC COUT = 10µF TA = 25°C 100 85°C 80 25°C – 40°C 60 40 VCC OUTPUT VOLTAGE (V) SHUTDOWN CURRENT (µA) OPERATING CURRENT (µA) NO EXTERNAL LOAD 15 10 85°C 25°C 5 5.1 5.0 4.9 – 40°C 2 6 8 4 VIN INPUT VOLTAGE (V) 10 0 4.8 6 8 4 VIN INPUT VOLTAGE (V) 2 10 1555/56 G01 VCC Output Voltage vs Input Voltage (3V Mode) 2 6 8 4 VIN INPUT VOLTAGE (V) 10 1555/56 G02 1555/56 G03 VCC Output Voltage Turn-On Time, SS Enabled VCC Output Voltage Turn-On Time, SS Disabled 3.1 1V/DIV IVCC = 10mA M0 = DVCC M1 = 0V COUT = 10µF TA = 25°C 1V/DIV VCC OUTPUT VOLTAGE (V) 3.2 3.0 2.9 VIN = 3V SS = 0V 2.8 2 6 8 4 VIN INPUT VOLTAGE (V) 1555/56 G05 1ms/DIV VIN = 3V SS = DVCC 1ms/DIV 10 1555/56 G04 3V VCC Efficiency vs Input Voltage 5V VCC Efficiency vs Input Voltage 100 100 VCC = 5V IVCC = 10mA TA = 25°C VCC = 3V IVCC = 10mA TA = 25°C 80 EFFICIENCY (%) EFFICIENCY (%) 80 60 40 40 20 20 0 2 6 8 4 VIN INPUT VOLTAGE (V) 10 1555/56 G07 4 60 2 4 8 10 6 VIN INPUT VOLTAGE (V) 12 1555/56 G08 1555/56 G06 LTC1555/LTC1556 U U U 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 1µA 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 M1 MODE 0V 0V Shutdown (VCC = 0V) 0V DVCC VCC = VIN DVCC 0V VCC = 3V DVCC DVCC VCC = 5V 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 10µF 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 10µF 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 U U U PIN FUNCTIONS ground, the regulator acts as a ≤ 30Ω switch between VCC and LDO. 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 1µA current source. 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 ≤ 30Ω power switch if the FB pin is grounded or left floating. When used as a regulator, LDO must be bypassed to GND with a ≥ 3.3µF capacitor. The LDO output current will subtract from available VCC current. 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 W BLOCK DIAGRAM VBATT + 0.1µF CIN 10µF C1+ C1– VIN VCC M1 STEP-UP/ STEP-DOWN CHARGE PUMP DC/DC CONVERTER M0 3V VCC COUT 10µF SS DVCC VCC RIN RST CIN CLK RST CONTROLLER SIM 20k CLK 10k DATA I/O I/O 1µA OPTIONAL DDRV GND GND EN 1µA 1.23V FB 153k – GND + LDO 4.3V + 61k LTC1555/LTC1556 LTC1556 ONLY 1555/56 BD 6 CLDO 10µF FREQUENCY SYNTHESIZER POWER LTC1555/LTC1556 U W U U 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 = 10µF). 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 (< 0.5Ω) 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 10µF or greater (ceramic capacitors will produce the smallest output ripple). If the input source impedance is very low (< 0.5Ω), CIN may not be needed. Increasing the size of COUT to 22µF 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 0.1µF or 0.22µF. 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, 10µF output capacitor. For applications requiring VIN to exceed 8V, a 22µF 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 (> 0.22µF) also increases ripple in step-up mode for the same reason. Large output current load and/or a small output capacitor (< 10µF) results in higher ripple due to higher output voltage dV/dt. High ESR capacitors (ESR > 0.5Ω) on the output pin cause high frequency voltage spikes on VOUT with every clock cycle. A 10µF 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 7 LTC1555/LTC1556 U W U U APPLICATIONS INFORMATION reduce the ripple. A larger COUT capacitor (22µF 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 (10µF or greater). A reasonable compromise is to use a 10µF to 22µF tantalum capacitor in parallel with a 1µF to 3.3µF 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). 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 VCC + 15µF TANTALUM 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 SIM VCC 1µF CERAMIC LTC1555/ LTC1556 VCC 2Ω 10µF SIM VCC 10µF LT1555/56 F01 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 LTC1555/LTC1556 CLK TO SIM CIN CLK RST TO SIM RIN RST DATA TO/FROM SIM CONTROLLER SIDE DATA I/O DDRV VCC DVCC SIM SIDE 1555/56 F3a DVCC Figure 3a. Level Translator Connections for Bidirectional Controller DATA Pin M0 0V DVCC LTC1555/LTC1556 M1 0V CLK TO SIM CIN CLK DVCC RST TO SIM RIN RST 0V DATA FROM SIM DATA I/O DATA TO SIM DDRV VCC DVCC VCC CONTROLLER SIDE VCC 0V DVCC SIM SIDE 1555/56 F3b 1555/56 F02 Figure 2. Recommended DVCC Shutdown and Start-Up Timing 8 Figure 3b. Level Translator Connections for One-Directional Controller Side DATA Flow LTC1555/LTC1556 U W U U 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 100µA) 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 3.3µF (minimum) capacitor is required to ensure output stability. A 10µF 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 1µA VREF FB 153k 61k – + VCC = 5V LDO 4.3V + ILDO 0mA to 10mA 10µF TANT 1555/56 F04 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/1.5kΩ) 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. 9 LTC1555/LTC1556 U PACKAGE DESCRIPTION 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 × 45° (0.38 ± 0.10) 0.007 – 0.0098 (0.178 – 0.249) 4 5 6 7 8 0.004 – 0.0098 (0.102 – 0.249) 0° – 8° TYP 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 10 0.053 – 0.068 (1.351 – 1.727) 2 3 0.008 – 0.012 (0.203 – 0.305) 0.025 (0.635) BSC GN16 (SSOP) 1197 LTC1555/LTC1556 U PACKAGE DESCRIPTION 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 × 45° (0.38 ± 0.10) 0.007 – 0.0098 (0.178 – 0.249) 2 3 4 5 6 7 8 0.053 – 0.068 (1.351 – 1.727) 9 10 0.004 – 0.0098 (0.102 – 0.249) 0° – 8° TYP 0.016 – 0.050 (0.406 – 1.270) 0.008 – 0.012 (0.203 – 0.305) 0.025 (0.635) BSC * 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. GN20 (SSOP) 1197 11 LTC1555/LTC1556 U TYPICAL APPLICATION SIM Interface with Auxilary Power + 10µF 3V GSM CONTROLLER 3V 2 3 4 5 6 VCC VIN 2.7V TO 10V LTC1556 1 7 8 9 10 CIN CLK RIN RST CLK 19 RST 18 I/O DDRV LDO EN VCC FB VIN DVCC C1 + 14 SS C1 – 13 M1 GND GND SIM 20 DATA M0 4.3V 50mA AUXILIARY LDO/POWER SWITCH (FREQUENCY SYNTHESIZER) I/O 17 16 VCC 5V ± 5% IVCC ≤ 10mA 15 0.1µF 10µF + 12 11 10µF GND 1555/56 TA02 RELATED PARTS PART NUMBER DESCRIPTION LTC1514-3.3/LTC1514-5 Regulated Step-Up/Step-Down Charge Pumps with Low Bat Comparator 3.3V and 5V Output Versions COMMENTS LTC1515 Series Regulated Step-Up/Step-Down Charge Pumps with Reset Output Adjustable, 3V/5V, 3.3V/5V Versions LTC1516 Micropower, Regulated 5V Charge Pump DC/DC Converter IOUT = 20mA (VIN ≥ 2V), IOUT = 50mA (VIN ≥ 3V) LTC1517-5 Micropower, Regulated 5V Charge Pump DC/DC Converter LTC1522 Without Shutdown and Packaged in SOT-23 LTC1522 Micropower, Regulated 5V Charge Pump DC/DC Converter IOUT = 20mA (VIN ≥ 3V), IQ = 6µA LTC1550-4.1 Low Noise, Charge Pump Voltage Inverter 1mVP-P Ripple at 900kHz LTC660 100mA Charge Pump DC/DC Converter 5V to – 5V at 100mA 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 ● (408) 432-1900 FAX: (408) 434-0507● TELEX: 499-3977 ● www.linear-tech.com 15556f LT/TP 0398 4K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1997