Low-Cost, Multiple-Output Power Supply for LCD TVs and Monitors
SUNNYVALE, CA-February 23, 2006-Maxim Integrated Products (NASDAQ:
MXIM) introduces the MAX8728 power supply, which generates all supply
rails for thin-film transistor (TFT), liquid-crystal display (LCD)
panels in TVs and monitors. It 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 has
a 7V to 13.2V input supply voltage, and is optimized for LCD TV panel
and LCD monitor applications running directly from 12V supplies.
The MAX8728's step-up and step-down regulators feature internal power
MOSFETs and high-frequency operation. This allows the use of small
inductors and capacitors, resulting in a compact solution. 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. Both output 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 startup. An
integrated current-limit function for internal switches and
output-fault shutdown protects the power supplies against fault
conditions. The MAX8728 also provides adjustable power-up timing.
The MAX8728 is available in a small (5mm x 5mm), low-profile (0.8mm),
32-pin TQFN package, and operates over the -40 degrees Celsius to +85
degrees Celsius temperature range. Prices start at $4.15 (1000-up,
FOB USA). A preassembled MAX8728 evaluation kit with recommended
external components is available to reduce design time.
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