Texas Instruments’ TPS60250 drives up to five white LEDs for a main display and up to two white LEDs for a sub-display with regulated constant current for uniform intensity. The high-efficiency, constant-frequency charge-pump dc-dc converter uses dual-mode conversion to maximize efficiency over the single-cell lithium-battery input voltage range. The device also provides a fully programmable current via an I2C interface.
By utilizing adaptive charge pump modes and very low-dropout current regulators, the TPS60250 achieves high efficiency. To lower operating current when using one sub-display LED, the device provides completely separate operation in sub-display LEDs. The TPS60250 is packaged in a 3-mm x 3-mm, 16-pin QFN package. Suggested pricing starts at $1.40 in 1000-unit quantities.