Integrated High-Current LED Driver in Chip Scale Package

13th June 2007

ES Admin

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Texas Instruments has introduced a device based on a high-frequency synchronous-boost topology with constant current sink to drive single, high-brightness white light emitting diodes (LEDs). The tiny 2 mm x 1.5 mm x 0.625mm device uses an inductive fixed-frequency pulse-width modulation (PWM) control scheme using small external components, minimizing input ripple current for applications, such as a white LED flash for camera phones, smart phones and PDAs and other general lighting applications and reduces total solution size to less than 25 mm2.

TI's TPS61050 integrated circuit (IC) use a 2-MHz switching frequency that allows the use of small and low-profile 2.2-µH inductors. The TPS61050 device operates as a regulated current source, as well as a
standard voltage-boost regulator. This additional operating mode can be useful to supply other high-power devices in the system, such as an audio power amplifier, or any other component requiring a supply voltage higher than the battery voltage.

For highest flexibility, the device's LED current or the desired output voltage can be programmed via an I2C compatible interface. The TPS61050 also simplifies design by integrating four pre-set operation modes. To simplify flash synchronization with the camera module, the device offers a trigger pin for fast LED turn-on time. When the TPS61050 is not in use, it enters into shutdown mode via the I2C-compatible interface, reducing the input current to 0.3 µA. During shutdown, the LED pin is high impedance to avoid leakage current through the LED.

The LED Driver is shipping in volume production today from TI and its worldwide network of distributors and packaged in a 2 mm x 1.5 mm, 12-pin wafer chip scale and 10-pin QFN packaging. Suggested resale
price starts at $1.40 in 1,000-unit quantities.