New Industry Products

Digitally Programmable USB/AC Li-Ion Charger from Summit

February 20, 2006 by Jeff Shepard

Summit Microelectronics has announced the first product in a family of programmable Li-ion charger IC's aimed at the latest portable consumer applications. Specially designed to operate with the popular Universal Serial Bus (USB) and other current-limited power sources, the SMB135 offers flexible single cell Li-ion and Li-polymer battery charging.

Combining switch-mode operation with Summit's proprietary Turbo Charge™ mode the SMB135 dramatically cuts charge time, shrinking or eliminating costly and bulky external ac-dc power supplies. The SMB135 also eliminates power cables and connectors by allowing standardization to a single mechanical connector (USB) for power and data, thereby reducing system cost and complexity.

The SMB135 includes a 1A current-mode step-down (buck) switching battery charger with 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 I2C/SMBus interface enabling a wide variety of algorithms without hardware changes.

"Leveraging Summit's field-proven programmable power management technology the SMB135 sets new standards for Li-Ion battery charging in portable systems. Switch-mode operation and a programmable algorithm enable huge gains in charge time, power dissipation, solution size and safety," stated Abid Hussain, Summit's Director of Marketing. "The SMB135 is a truly ground-breaking product that will enable a new generation of 'ultra-mobile' devices by simplifying the critical battery charging function."

The programmable algorithm combined with the inherent current multiplication effect of the switching regulator enables Summit's Turbo Charge™ mode that delivers up to 750mA charging current from a standard 500mA USB port (up to 1A from an AC/DC adapter). This represents more than double the charge current typically available from competing solutions, cutting the battery charge time by as much as 66%.

The SMB135 is designed for use in handheld consumer electronics devices such as 2.5G/3G phones, PDAs/smartphones, Bluetooth headsets, portable media players (PMP), portable game consoles, digital still cameras (DSC)/camcorders (DCC) and GPS terminals. In particular it is the ideal battery charging solution for applications that use a single USB connector to provide both data and power.

The SMB135 has an operating temperature range of 0 degrees C to +70 degrees C and is available in the 1.3mm x 2.1mm 15-ball chip-scale (CSP™) package that is lead-free and RoHS-standards compliant. Available now in production quantities, the device is priced at $0.98 each in quantities of 10,000 units.