LTC1756 Linear Technology, LTC1756 Datasheet
LTC1756
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LTC1756 Summary of contents
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... GND READY LTC1756 I/O I/O 7 RST RST 8 CLK CLK Final Electrical Specifications LTC1756 Smart Card Interface February 2000 U 1756 universal Smart Card interface is fully 16 5V/3V 15 CARD 14 13 – C CONTROLLER C1 0. DATA 10 RIN 9 CIN 1756 TA01 ...
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... PWR to READY OUT I = 0mA 5V VCC CC OUT Source Current = 20 A Sink Current = – 500 A (Note 3) Loaded with 30pF, 10% to 90% PWR = ORDER PART NUMBER TOP VIEW 16 5V/3V LTC1756EGN 15 CARD 14 READY – DATA 10 RIN 9 CIN GN PACKAGE = 125 C, = 135 C/W JA MIN ...
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... PRES Debounce Time Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC1756 is guaranteed to meet performance specifications from Specifications over the – operating temperature range are assured by design, characterization and correlation with statistical process controls ...
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... below its correct level (for as little the LTC1756 switches to the Alarm state (see the State Diagram). The V pin requires charge storage CC capacitor to ground. For optimum performance a low ESR ceramic capacitor should be used ...
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... CC The READY pin is configured as an open-drain pull-down with a weak pull-up current source. The READY pin also indicates if the LTC1756 is in Alarm mode. The LTC1756 detects faults such as V for at least 5 s, overtemperature shutdown, CLK or RST pin has ...
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... LTC1756 W BLOCK DIAGRA V IN PRES 1 PWR 2 GND I/O 6 RST 7 CLK 8 * DYNAMIC PULL-UP CURRENT SOURCE 6 DC/DC CONVERTER AND CONTROL LOGIC * 16 5V/3V 15 CARD 14 READY – DATA 10 RIN 9 CIN 1756 BD ...
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... CC close to the V pin and tied immediately to the ground CC plane. Capacitor Selection The style and value of capacitors used with the LTC1756 determine several parameters such as output ripple volt- age, charge pump strength, Smart Card switch debounce time and V discharge rate. CC Due to the switching nature of a capacitive charge pump, ...
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... Low Power Operation The LTC1756 is inherently a low power device. When there is no Smart Card present the supply current is less than 2.5 A. When a Smart Card is present the LTC1756 oper- ates with a quiescent current of only 75 A, thus the majority of power is consumed by charge pump losses and the card itself ...
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... U APPLICATIONS INFORMATION Self-Start Mode By connecting the CARD pin to the PWR pin the LTC1756 can be made to start up automatically when a Smart Card is detected (Figure 2). In this mode, the READY pin becomes an interrupt signal indicating to the microcon- troller that a Smart Card is present and that V pump voltage its final value ...
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... CC An activation command (PWR = 0V) will only be acknowl- edged once this occurs. ALARM/DEACTIVATION The only possible next state is Idle/Deactivation which is achieved by disabling the LTC1756 via the PWR pin (i.e., PWR = The alarm indication can be cleared by rapidly cycling the PWR pin. However, a new activation cycle will not begin until has dropped below approximately 1V ...
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... TYP 0.008 – 0.012 (0.203 – 0.305) LTC1756 0.189 – 0.196* (4.801 – 4.978) 0.009 (0.229 REF 0.150 – 0.157** (3.810 – 3.988) ...
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... LTC1756 RELATED PARTS PART NUMBER DESCRIPTION LTC1514/LTC1515 Micropower Step-Up/Step-Down Inductorless DC/DC Converters LTC1516 Micropower Regulated 5V Charge Pump LTC1555/LTC1556 SIM Power Supply and Level Translator LTC1754-5 5V Charge Pump with Shutdown in SOT-23 LTC1755 Smart Card Interface with C4, C8 Pins LTC1986 3V/5V SIM Power Supply in SOT-23 ...