MAX8728

The MAX8728 generates all the 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 dualmode,logic-controlled high-voltage switch control block.The MAX8728 can operate from input voltages from 7V to 13.2V and is optimized for LCD TV panel and LCD monitor applications running directly from 12V supplies.

Features of the MAX8728 are:(1)optimized for 10.8V to 13.2V input supply; (2)7V to 13.2V input supply range; (3)selectable frequency (500kHz/1MHz/1.5MHz); (4)current-mode step-down regulator; (5)adjustable positive/negative charge pumps; (6)soft-start and timer delay fault latch for all outputs; (7)logic-controlled, high-voltage switches; (8)power-up and power-down sequences; (9)thermal-overload protection.The step-up and step-down regulators feature internal power MOSFETs and high-frequency operation allowing 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 absolute maximum ratings of the MAX8728 can be summarized as:(1)operating temp:-40 to 85;(2)storage temperature range:-65 to +160;(3)lead temperature (soldering, 10s) :+300;(4)IN, INL, SUPP to GND:-0.3V to +14V;(5)BST to GND1:-0.3V to +20V.Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.The MAX8728 is a multiple-output power supply designed primarily for TFT LCD panels used in monitors and TVs. It contains a step-down switching regulator to generate the logic supply rail, a step-up switching regulator to generate the source driver supply, and two charge-pump regulators to generate the gate-driver supplies. Each regulator MAX8728 features adjustable output voltage,digital soft-start, and timer-delayed fault protection.Both the step-down and step-up regulators use fixedfrequency current-mode control architectures.