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This literature is subject to all applicable copyright laws and is not for resale in any manner.FAN5421 Single-Cell Li-Ion Switching Charger May 2013 FAN5421 Single-Cell Li-Ion Switching Charger Features Description The FAN5421 is a highly integrated switched-mode charger Fully Integrated, High-Efficiency Charger for Single-Cell that minimizes single-cell Li-Ion charging time. Li-Ion and Li-Polymer Battery Packs The charging parameters and operating modes are Faster Charging than Linear 2 programmable through an I C interface that operates up to Charge Voltage Accuracy: 0.5% at 25C 3.4 Mbps. The charger circuit switches at 3 MHz to minimize 1% from 0 to 125C the size of external passive components. 5% Charge Current Regulation Accuracy The FAN5421 provides battery charging in three phases: conditioning, constant current, and constant voltage. 20 V Absolute Maximum Input Voltage Charge termination is determined by a programmable 6.8 V Maximum Input Operating Voltage minimum current level. A safety timer with reset control 2 1.5 A Maximum Charge Rate provides a safety backup for the I C host. Charge and Mode Programmable through High-Speed The IC automatically adapts to current-limited power sources 2 I C Interface (3.4 Mb/s) with Fast Mode Plus Compatibility by reducing the charge current to keep the input supply Fast Charge / Termination Current above a programmed voltage (default 4.52 V). Charger Voltage The IC automatically restarts the charge cycle when the battery falls below an internal threshold. If the input source is Safety Timer removed, the IC enters a high-impedance mode with leakage Termination Enable from the battery to the input prevented. Charge status is 2 3 MHz Synchronous Buck PWM Controller with Wide Duty reported back to the host through the I C port. Charge Cycle Range current is reduced when the die temperature reaches 120C. Small-Footprint, 1H External Inductor The FAN5421 is available in a 1.96 x 1.87 mm, 20-bump, 0.4 mm pitch, Wafer-Level Chip-Scale Package (WLCSP). Safety Timer with Reset Control Low Reverse Leakage to Prevent Battery Drain to VIN Applications Cell Phones, Smart Phones, PDAs Digital Cameras Portable Media Players Figure 1. Typical Application Table 1. Ordering Information Part Number Temperature Range Package PN Bits: IC INFO 4:3 Packing (1) FAN5421BUCX -40 to 85C WLCSP-20, 0.4 mm Pitch 00 Tape and Reel Note: 1. Includes backside laminate 2011 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN5421 Rev. 1.0.2