Catalog
Adjustable TFT Bias Supply with WLED Driver
Key Features
• 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
• VINRange 2.5V to 6V, VOUTRange 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)
Description
AI
The LTC3524 is an integrated BIAS and white LED power converter solution for small/medium-sized polysilicon thin film transistor (TFT) liquid crystal (LCD) display panels. The device operates from a single Lithium-Ion/polymer battery or any voltage source between 2.5V and 6V.A 1.5MHz synchronous boost converter generates a programmable low noise, high efficiency 25mA TFT supply of up to 6.0V. Regulated, low ripple charge pumps are used to generate up to +20V and –20V at 2mA. Output sequencing is internally controlled to insure proper initialization and rapid discharge of the LCD panel in shutdown.A second 1.5MHz boost converter powers one or two LED strings with up to five series elements each. LED current and display brightness can be controlled over a wide range using analog or digital means up to 25mA.The LTC3524 is offered in the 4mm × 4mm 24-pin QFN package, minimizing the total solution footprint.ApplicationsPDAs, Palmtop ComputersDigital Still and Video CamerasHandheld GPSPortable Instrument DisplaysPortable Media Players