ltc3455euf-trpbf Linear Technology Corporation, ltc3455euf-trpbf Datasheet
ltc3455euf-trpbf
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ltc3455euf-trpbf Summary of contents
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... QFN package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Swap is a trademark of Linear Technology Corporation. trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. *Protected by U.S. Patent including 6522118. MODE HSON ON2 µ ...
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... ON2 = 1V MODE = 1.35V WALLFB = 0V 100µA ON PBSTAT = 0V 1mA ON PBSTAT = 100µA = 1mA U W TOP VIEW ORDER PART NUMBER LTC3455EUF 18 FB2 HSON 14 HSO UF PART 13 HSI MARKING 3455 UF PACKAGE = 36°C/W, θ ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are 0V unless otherwise noted. USB WALLFB PARAMETER CONDITIONS Battery-V PMOS MAX V PMOS Switch On-Resistance MAX V Switch Current Limit MAX V Switch Current Limit at ...
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LTC3455 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are 0V unless otherwise noted. USB WALLFB PARAMETER CONDITIONS Battery Charger 0°C ≤ T Regulated Charger V Voltage BAT Charger Current Limit (USB Powered ...
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W U TYPICAL PERFOR A CE CHARACTERISTICS Feedback Pins (FB1, FB2) and AI Pin Voltage 815 810 AI 805 800 FB1 FB2 795 790 785 – 100 125 –25 0 TEMPERATURE (°C) 3455 G04 USB Pin Current ...
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LTC3455 W U TYPICAL PERFOR A CE CHARACTERISTICS Battery Charger Regulation Voltage 4.30 4.25 4.20 4.15 4.10 4.05 4.00 – 100 –25 0 TEMPERATURE (°C) 3455 G13 Charge Current When Wall-Powered 600 500 400 THERMAL CONTROL LOOP ...
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CTIO S FB1 (Pin 1): Feedback Pin for Switcher 1. Set the output voltage by connecting feedback resistors to this pin. PROG (Pin 2): Charge Current Program and Charge Cur- rent Monitor Pin. Connect a ...
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LTC3455 CTIO S FB2 (Pin 18): Feedback Pin for Switcher 2. Set the output voltage by connecting feedback resistors to this pin. ON2 (Pin 19): Enable Pin for Switcher 2. This pin turns on Switcher ...
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W BLOCK DIAGRA USB POWER MANAGER USB USB 8 5V 1Ω 5.6V 4.7µF – REF + SUSPEND 6 USB CONTROLLER USBHP 5 1k CHRG V 4 MAX TIMER 3 PROG 2 0.1µF 2.49k GND BAT BAT 9 ...
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LTC3455 U OPERATIO The LTC3455 is designed complete power manage- ment solution for a wide variety of portable systems. The device incorporates two current mode step-down switch- ing regulators, a full-featured battery charger, a USB power controller, ...
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U U APPLICATIO S I FOR ATIO Operation When No Battery Is Present As long as USB or wall power is available, the LTC3455 will operate with no battery present, a crucial requirement for systems with a removable battery. Keep ...
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LTC3455 U U APPLICATIO S I FOR ATIO USB High Power/Low Power/Suspend Modes There are three basic modes for the USB power manager: high power, low power, and suspend. High power mode allows the LTC3455 to draw up to 500mA ...
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U U APPLICATIO S I FOR ATIO Handling Large Transient Loads when USB Powered Many portable devices have nominal loads that can easily be supported by the USB supply, but they have brief transient loads that can exceed the maximum ...
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LTC3455 U U APPLICATIO S I FOR ATIO Using the V Pin to Power Other Devices MAX The V pin can be used to provide power for other MAX devices within the system. This pin is connected to the battery ...
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U U APPLICATIO S I FOR ATIO ON2 19 23 PBSTAT PWRON V 9 BAT WALLFB 11 USB 8 SUSPEND 6 Startup and Shutdown When USB or Wall Powered Whenever USB or wall power is present (as ...
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LTC3455 U U APPLICATIO S I FOR ATIO Low or Bad Battery Protection (200ms Timeout) The 200ms reset timer is also used to prevent starting the LTC3455 when there is insufficient external power or insufficient battery voltage to regulate the ...
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U U APPLICATIO S I FOR ATIO Switching Regulator Inductor Selection Many different sizes and shapes of inductors are available from numerous manufacturers. Choosing the right induc- tor from such a large selection of devices can be over- whelming, but ...
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LTC3455 U U APPLICATIO S I FOR ATIO USB Pin and Wall Adapter Capacitor Selection The USB and wall adapter inputs should be bypassed with a 4.7µF to 10µF capacitor. For some applications, the wall input can be bypassed locally ...
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... Output voltage ripple is slightly higher in this mode, but efficiency is greatly improved. As shown in Figure 8, the efficiency at low load currents increases significantly when Burst Mode operation is used. Burst Mode is a registered trademark of Linear Technology Corporation. 100 Burst Mode 3. ...
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LTC3455 U U APPLICATIO S I FOR ATIO Soft-Start for each Switcher Soft-start is accomplished by gradually increasing the peak inductor current for each switcher. This allows each output to rise slowly, helping minimize the battery in-rush current. Figure 10 ...
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U U APPLICATIO S I FOR ATIO Programming Charge Current The maximum charge current is programmed using one external resistor connected between the PROG pin and GND (use the closest 1% resistor value 1000 • 1.23V / I ...
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LTC3455 U U APPLICATIO S I FOR ATIO Battery Charger Thermal Limit An internal thermal limit reduces the charge current if the die temperature attempts to rise above approximately 105°C. This protects the LTC3455 from excessive tem- perature, and allows ...
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U U APPLICATIO S I FOR ATIO Hot Swap Output A current limited Hot Swap output is provided for power- ing memory cards or other external devices that can be hot-plugged into the system. Typically connected to the 3.3V supply, ...
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LTC3455 U U APPLICATIO S I FOR ATIO V OUT1 C1 VIAS TO LOCAL GROUND PLANE. Figure 15. Recommended Board Layout and Component Placement for Power Sections of LTC3455 (Refer to Schematic on Back Page ...
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U TYPICAL APPLICATIO S Standalone USB Power Supply with Temporary Backup Power Although designed primarily for Li-Ion powered portable applications, the LTC3455 is also a good choice for systems that are always powered by a USB supply or wall adapter. ...
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LTC3455 U TYPICAL APPLICATIO S Increasing 3.3V Output Current to 1.2A With an internal current limit of 900mA, Switcher 2 typi- cally provides a 3.3V, 600mA output. While this output current is sufficient for many portable devices, some applications need ...
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... SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights Package 24-Lead Plastic QFN (4mm × ...
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... IN OUT(MIN 2. 0.8V 20µA, IN OUT(MIN 2.5V to 5.5V 0.6V 20µA, IN OUT(MIN 2.5V to 5.5V 0.6V 40µA, IN OUT(MIN 2.5V to 5.5V 0.8V 60µA, IN OUT(MIN 2.25V to 5.5V 0.8V 64µA, IN OUT(MIN 2.5V to 5.5V 2.5V 25µA/50µA, IN OUT(MIN 0606 REV B • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2006 3455fb ...