Sunnyvale, Calif.—Maxim's MAX8728 power supply IC generates all the supply rails for thin-film transistor (TFT) liquid-crystal display (LCD)
panels in TVs and monitors. The chip includes step-down and step-up regulators, positive and negative charge pumps, and a dual-mode, logic-controlled, high-voltage switch-control block.
The MAX8728, which provides 3.3-volt logic, 13.5-volt source driver, 28-volt positive gate driver, and -6 volt negative gate supplies, is optimized for LCD TV panel and LCD monitor applications running from a 12-volt source. The MAX8728's step-up and step-down regulators feature internal power MOSFETs, and its high-frequency operation allows the use of small inductors and capacitors. Both switching regulators use fixed-frequency, current-mode control architectures, providing fast load-transient response and easy compensation.
The positive and negative charge-pump regulators,
provide TFT gate-driver supply voltages, can be adjusted with external resistive voltage dividers. The switch-control block allows the manipulation of the positive TFT gate-driver voltage. Soft-start functions limit inrush current during start-up. An integrated current-limit function for internal switches and output-fault shutdown protects the chip against fault conditions. The MAX8728 also provides adjustable power-up timing.
Click here to access the product datasheet. The MAX8728, in a 5-by-5 mm, low-profile (0.8mm) 32-pin TQFN package and rated for operation over -40 to +85°C, is priced starting at $4.15 each (1000-up, FOB USA). A preassembled MAX8728 evaluation kit with recommended external components is available to reduce design time.
Maxim Integrated Products, 1-800-998-8800, www.maxim-ic.com