STMicroelectronics’ Backlight Driver for High-Tech Handhelds
Saves Power, Time and Money
Miniature control IC for energy-efficient white-LED backlights simplifies circuit design
Geneva, September 28, 2011 – STMicroelectronics has extended its portfolio of energy-saving solutions for mobile devices with a new IC that simplifies the design of power-efficient LCD and keypad backlights comprising white LEDs.
Backlights built with white LEDs, instead of traditional fluorescent tubes, consume less power enabling longer battery life for portable devices such as smartphones, games and GPS terminals. 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.