LTC3455EUF#TRPBF Linear Technology, LTC3455EUF#TRPBF Datasheet
LTC3455EUF#TRPBF
Specifications of LTC3455EUF#TRPBF
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LTC3455EUF#TRPBF Summary of contents
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... QFN package. L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 6522118. MODE ...
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... Storage Temperature Range- ................. –65°C to 125°C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LTC3455EUF#PBF LTC3455EUF#TRPBF LTC3455EUF-1#PBF LTC3455EUF-1#TRPBF Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based fi nish parts. ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are 0V unless otherwise noted. USB WALLFB PARAMETER CONDITIONS ON Pin Pullup Current V ON PWRON Pin Pulldown Current V PWRON ON2 Pin Pulldown Current V ...
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LTC3455/LTC3455-1 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are 0V unless otherwise noted. USB WALLFB PARAMETER CONDITIONS Hot Swap Output Hot Swap PMOS Switch On-Resistance V HSI Hot Swap PMOS Switch Current Limit ...
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TYPICAL PERFORMANCE CHARACTERISTICS Feedback Pins (FB1, FB2) and AI Pin Voltage 815 810 AI 805 800 FB1 FB2 795 790 785 –50 – 100 TEMPERATURE (°C) 3455 G04 USB Pin Current Limit 500 USBHP = 2V ...
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LTC3455/LTC3455-1 TYPICAL PERFORMANCE CHARACTERISTICS Battery Charger Regulation Voltage 4.30 4.25 LTC3455 4.20 4.15 LTC3455-1 4.10 4.05 4.00 –50 – 100 TEMPERATURE (°C) 3455 G13 Charge Current When Wall-Powered 600 500 400 THERMAL CONTROL LOOP IN OPERATION ...
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PIN FUNCTIONS 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 resistor ground to ...
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LTC3455/LTC3455-1 PIN FUNCTIONS 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 2 only ...
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BLOCK DIAGRAM USB POWER MANAGER USB 8 USB 5V 1Ω 5.6V 4.7μF – REF + SUSPEND 6 R USB CONTROLLER USBHP CHRG V 4 MAX TIMER 3 PROG 2 0.1μF 2.49k GND BAT BAT ...
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LTC3455/LTC3455-1 OPERATION The LTC3455/LTC3455-1 are designed complete power management solution for a wide variety of portable systems. The device incorporates two current mode step- down switching regulators, a full-featured battery charger, a USB power controller, a Hot ...
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APPLICATIONS INFORMATION Operation When No Battery Is Present As long as USB or wall power is available, the LTC3455/ LTC3455-1 will operate with no battery present, a crucial requirement for systems with a removable battery. Keep in mind, however, that ...
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LTC3455/LTC3455-1 APPLICATIONS INFORMATION 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/LTC3455-1 to draw up to 500mA from the USB port, and ...
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APPLICATIONS INFORMATION 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 tran- sient loads that can exceed the maximum available USB power. The ...
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LTC3455/LTC3455-1 APPLICATIONS INFORMATION 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 when no external power is ...
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APPLICATIONS INFORMATION ON2 19 PBSTAT PWRON V 9 BAT 3V WALLFB 11 1.23V 8 USB 3.9V SUSPEND 6 Startup and Shutdown When USB or Wall Powered Whenever USB or wall power is present (as sensed by ...
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LTC3455/LTC3455-1 APPLICATIONS INFORMATION Low or Bad Battery Protection (200ms Timeout) The 200ms reset timer is also used to prevent starting the LTC3455/LTC3455-1 when there is insuffi cient exter- nal power or insuffi cient battery voltage to regulate the outputs. When ...
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APPLICATIONS INFORMATION Switching Regulator Inductor Selection Many different sizes and shapes of inductors are avail- able from numerous manufacturers. Choosing the right inductor from such a large selection of devices can be overwhelming, but following a few basic guidelines will ...
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... Q characteristics of ceramic capacitors can cause substantial ringing which can easily exceed the maximum voltage pin ratings and damage the LTC3455/LTC3455-1. Refer to Linear Technology Applica- tion Note 88, entitled “Ceramic Input Capacitors Can Cause Overvoltage Transients” for a detailed discussion of this problem ...
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APPLICATIONS INFORMATION Programming Switching Regulator Output Voltage The output voltage for each switching regulator is pro- grammed using a resistor divider from the output connected to the feedback pins (FB1 and FB2): ⎛ ⎞ ⎜ ⎟ ...
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LTC3455/LTC3455-1 APPLICATIONS INFORMATION 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 shows the battery current during startup. A soft-start cycle ...
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APPLICATIONS INFORMATION 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 PROG BAT If only USB ...
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LTC3455/LTC3455-1 APPLICATIONS INFORMATION 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/LTC3455-1 from ex- cessive temperature, and allows the user to push the ...
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APPLICATIONS INFORMATION pin to GND. Since the charge cycle is terminated only by the charge timer, external charge termination is required when using either of these methods. Use an external NMOS to fl oat the PROG pin and disable charging. ...
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LTC3455/LTC3455-1 APPLICATIONS INFORMATION V OUT1 C1 VIAS TO LOCAL GROUND PLANE. Figure 15. Recommended Board Layout and Component Placement for Power Sections of LTC3455/LTC3455-1 (Refer to Schematic on Back Page) Standalone USB Power Supply with Temporary Backup Power Although designed ...
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TYPICAL APPLICATIONS using the battery charger to slowly charge this capacitor (normally using such a large capacitor would result in very large inrush currents). With the TIMER pin tied to USB 5V 1Ω C6 4.7μF DROPOUT Figure 16. Standalone USB ...
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LTC3455/LTC3455-1 TYPICAL APPLICATIONS USB 5V 1Ω C6 4.7μF WALL 5V 1Ω C7 4.7μF SINGLE CELL Li-ION 3. C8: X5R OR X7R CERAMIC L1, L2: TOKO DB318C D1: ON SEMI MBRM110E ALL RESISTORS 1% Figure 17. LTC3455/LTC3455-1 ...
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... 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 representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. LTC3455/LTC3455-1 UF Package 24-Lead Plastic QFN (4mm × ...
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... V = 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 0708 REV C • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2006 3455fc ...