1/21/2003 - Texas Instruments (TI) (NYSE: TXN) announced the smallest and most integrated single-cell lithium-ion (Li-Ion) and lithium-polymer (Li-Pol) battery charger to enable personal digital assistants (PDAs), cell phones, digital cameras and wireless headsets to charge from a universal serial bus (USB) port or AC wall adapter.
The bqTINYTM II series of battery chargers offer designers fully integrated, fully compliant USB port and AC adapter supply management capability through its autonomous power-source selection, power field effect transistor (FET) and current sensor, high accuracy current and voltage regulation, charge status and termination -- all on a single piece of silicon.
"As more designers build portable applications that require greater functionality, unique connectivity and longer battery life, TI continues to drive levels of integration in battery management integrated circuitry to simplify design and save board space and manufacturing cost," said Dave Heacock, worldwide general manager for TI's Portable Power Management Products. "With the bqTINY II's ability to automatically select a USB port or an AC adapter as the power source for the system, designers can quickly take to market space-limited portable applications with more options to stay powered up anytime, anywhere."
In USB configuration, the host device, such as a PDA or cell phone, can select from two preset charge rates of 100mA and 500mA. In AC adapter configuration, the integrated power FET allows up to 1A of charge current. An integrated current sensor with programmable current set-point provides design flexibility and eliminates the need for bulky external sense resistors.
As with other members of the bqTINYTM family, the new bqTINY II chargers integrate a reverse-blocking protection scheme to prevent battery drainage in the absence of the DC supply. Other integrated features include voltage and current regulation, safety timers for pre-charge and fast charge phases, charge status outputs to light-emitting diodes (LEDs) or a microcontroller, temperature sense and charge termination.
bqTINY II devices charge the battery in three phases required by battery cell manufacturers, including pre-charge conditioning, constant current and accurate constant voltage. The algorithm reduces charge times, maximizes total charge and protects the battery from thermal and electrical dangers. The charger re-starts the charge when the battery voltage falls below an internal threshold, and enters a low-power sleep mode when both supplies are removed. This unique deep-sleep feature prevents draining the battery during the absence of input power.
The bqTINY II ICs are now available in volume from TI and its authorized distributors. All bqTINY and bqTINY II devices are packaged in a 10-lead 3mm x 3mm QFN package.
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