Internal power MOSFETs and precision current sensing
High-accuracy float voltage regulation: 1%
Thermal regulation (current foldback)
Trickle charging
Pre-charge and complete-charge (36/240min) safety timers
Digital programming of all major parameters via I2C interface
- Fast charge voltage threshold, float voltage
- Pre-charge, fast charge, termination current
Status register monitors and flags charger operation
- Charge in-progress/termination
- Charge timer fault
- OC/UV/OV detection/shutdown
uCSP-19 lead-free package (0.4mm ball pitch)
APPLICATIONS
2.5/3/3G+ GSM/CDMA/WCDMA Phones
Smartphones/PDAs
Portable Media Players
Portable GPS Terminal
SMB138- Programmable Switch-mode, USB/AC Input Li+ Battery Charger with TurboCharge™ Mode and USB “On- the-Go” Power
INTRODUCTION
The SMB138 is a programmable single-cell lithium-ion/lithium-polymer battery charger designed for a variety of portable applications. The device provides a simple and efficient way to charge high-capacity Li-Ion batteries via a USB or AC adapter input. Unlike conventional devices, the SMB138’s high-efficiency, switch-mode operation eliminates the thermal problems of conventional linear solutions. Also the buck converter architecture effectively multiplies the input current to increase charge rate for the Li+ cell and uses current limited supplies like USB more efficiently. The SMB138 also supports USB On-the-Go devices by providing the required USB-OTG +5V power supply using the Li-Ion battery as a source.
The SMB138 can switch between USB mode and AC Adapter mode and works seamlessly in conjunction with a USB controller. Charge control includes qualification, trickle-charge, pre-charge, constant current/constant voltage, float voltage and termination/safety settings that are fully programmable via a serial I2C/SMBus and stored in non-volatile memory making the device truly a flexible solution. Fast charge current level can be set via I2C (limited in USB mode to ensure 100mA or 500mA input). Built-in is reverse-current blocking to prevent inadvertent cell discharge. High frequency operation and integrated power FETs contribute to reduced external component count and size.
The SMB138A device requires a user I2C command for charging initiation, whereas the SMB138C device powers up in the charging mode. The SMB138C offers the option to automatically charge the battery only when the battery voltage is below a selectable “dead-battery” threshold.
SUMMIT Microelectronics, Inc. reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. SUMMIT Microelectronics, Inc. assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained herein reflect representative operating parameters, and may vary depending upon a user’s specific application. While the information in this publication has been carefully checked, SUMMIT Microelectronics, Inc. shall not be liable for any damages arising as a result of any error or omission.
SUMMIT Microelectronics, Inc. does not recommend the use of any of its products in life support or aviation applications where the failure or malfunction of the product can reasonably be expected to cause any failure of either system or to significantly affect their safety or effectiveness. Products are not authorized for use in such applications unless SUMMIT Microelectronics, Inc. receives written assurances, to its satisfaction, that: (a) the risk of injury or damage has been minimized; (b) the user assumes all such risks; and (c) potential liability of SUMMIT Microelectronics, Inc. is adequately protected under the circumstances
Revision 3.0 - This document supersedes all previous versions.
