Adjustable TFT Bias Power Supply for TFT-LCDs & LED Driver in a 4 × 4mm QFN
Linear Technology announces the LTC3524, an integrated BIAS and white LED power converter solution for small to medium sized (3" to 7") thin film transistor (TFT) liquid crystal display (LCD) panels. The device operates from an input voltage range of 2.5V to 6V, enabling it to accommodate multicell alkaline/NiMH batteries as well as single cell Li-Ion. Each low noise output of the TFT converter is fully adjustable enabling it to power a wide array of LCD panels. The LTC3524 can generate up to 25mA at 6V for the AVDD channel, and up to 2mA at 20V and -20V for the respective VGH and VGL bias requirements with controlled power-up/power-down sequencing.
As the primary boost converter uses a synchronous rectification topology, the LTC3524 can deliver up to 90% efficiencies for the LCD biasing. The dual channel LED driver can power up to 10 white LEDs (5 per channel) while its True Color PWM™ Dimming offers up to 200:1 dimming ratios. Each LED channel is independent and offers open-LED protection. Total quiescent current is only 200uA, providing maximum battery life and its 1.5MHz switching frequency, combined with its 4mm × 4mm QFN package enables a tiny, low profile footprint.
The LTC3524EUF is available from stock in a 4mm × 4mm QFN package. Pricing starts at $2.25 for 1,000-piece quantities.
Summary of Features: LTC3524
- Generates Three Adjustable, Low Noise Rails for Small/Medium TFT Displays
- Drives Up to Ten White LEDs
- LED Dimming and Open-Circuit Protection
- Controlled Power-Up/Power-Down Sequencing
- 1.5MHz Fixed Frequency, Low Noise Operation
- VIN Range 2.5V to 6V, VOUT Range 3V to 6V
- TFT Supply Efficiency Up to 90%
- LED Supply Efficiency Up to 78%
- Two Independently Enabled LED Strings
- 200 to 1 True Color PWM Dimming
- Tiny External Solution
- 24-Lead QFN Package (4mm × 4mm × 0.75mm)
Adjustable TFT Bias Supply with LED for LCD Displays
Editor's Contact Information
- Doug Dickinson