Tiny charger IC fits slimmer portable apps

Summit Microelectronics has released the SMB239 charger IC that enables slimmer designs for portable consumer electronics. Housed in a tiny 2.1mm x 1.3mm CSP package, the SMB239 is touted to be the smallest charger IC for single-cell Li-Ion and Li-Polymer batteries.

The device's battery charging parameters are fully programmable via the I?C interface and non-volatile memory, allowing easy system design without any hardware changes. A set of safety features are incorporated, offering high system reliability and protection and eliminating the need for external safety components.

The SMB239 comprises a highly integrated, 500mA linear charging solution that utilizes a fully programmable algorithm for single-cell Li-ion and Li-Polymer cells. All charging parameters—pre-charge/fast-charge/charge termination current, cell float/pre-charge voltage, battery temperature/timer safety limits—are configurable via the IC/SMBus interface, enabling a wide variety of algorithms without hardware changes.

Default (custom) configuration in non-volatile memory allows the same product to be used in different system designs and/or with different battery types and technologies, resulting in significantly lower qualification/inventory costs and sourcing risks.

Host/software control capability allows in-system adjustment of the charging profile, minimizing charging time and enhancing safety.

The SMB239 requires just two small external chip capacitors for a complete battery charging system design. The SMB239's chip-scale package allows the integration of a higher number of features, including critical charging protection functionality.

Safety guaranteed
In addition, the SMB239 integrates a complete set of safety features to meet the strictest safety standards, including IEEE1725. These include input and battery over-voltage protection and blocking (+10V), current limit, chip and battery thermal protection, safety timers, battery missing detection and a variety of status and fault registers.

A STATUS output pin is available for indicating charge status and fault conditions.

The SMB239 allows the system to initiate battery charging only when battery voltage is below a certain threshold, thereby eliminating frequent charge cycles that may affect battery life.

The SMB239 is suitable for a wide range of portable devices, including Bluetooth mono/stereo headsets and other accessories, mobile phones, digital cameras, portable music players, portable GPS navigation, and handheld medical equipment. The features, size and integration of theSMB239 make it especially suited for devices that include a USB interface because it allows a tiny, low-cost, industry-standard micro USB connector to be the primary data and power/charging interface.

The SMB239 operates with an input range from +4.35V to +6.5V input and safely withstands continuous input over-voltage up to +10V (non-operating), while protecting downstream circuitry.

Ensuring long battery life when not connected to a DC power source, the device's reverse leakage current is less than 2?A.

The SMB239 is offered in a tiny 2.1mm x 1.3mm, 8-ball, Pb-free CSP package (0.5mm ball pitch) with an operating temperature range of -30°C to +85°C.

Available now in production quantities, the SMB239 is priced at $0.81 each in quantities of 10,000 units.

- Toni McConnel
Embedded.com