STMicroelectronics’ Backlight Driver for High-Tech Handhelds Saves Power, Time and Money - Miniature control IC for energy-efficient white-LED backlights simplifies circuit design

ST’s new chip, the STLA02, improves backlight design further by performing high-side current sensing, which allows the backlight negative (low-side) terminal to be connected directly to ground with no need for a low-side sensing connection. This simplifies pc-board design, reduces wired connections to the backlight, and increases system reliability.

The STLA02 can drive up to six LEDs and can operate from a supply voltage as low as 2.5V, allowing its use in systems powered by only a single lithium cell. The maximum input voltage of 18V also allows use with a variety of other battery types.

The STLA02 expands ST’s already large portfolio of devices that help reduce size and increase battery life in feature-rich portable products, leveraging in-house process technologies for class-leading integration and power efficiency. These include highly efficient DC-DC converters, audio ICs and class-D amplifiers, ambient light sensors, motion sensors, and high-performance low-power microcontrollers such as the STM8 and STM32 families.

Key features of STLA02:
• Boost (step-up) DC-DC converter topology
• Battery supply voltage range: 2.5V to 18V
• Maximum LED driving voltage: 27V
• Output current: 20mA per LED
• Switching frequency: 2.3MHz
• PWM dimming range: 300:1
• Enable pin with fast response due to current-mode regulation
• Built-in over-temperature and over-voltage protection

The STLA02 is in full production in the 6-lead DFN6 package, priced from $0.892 for orders over 1000 units. Alternative pricing options may be available for larger quantities.