MAX1531

· 4.5V to 28V Input Voltage Range
· 250kHz/500kHz Current-Mode Step-Down ConverterSmall Inductor/CapacitorsNo Sense Resistor
· Three Positive Linear Regulator ControllersOne Positive and One Negative AdditionalController (MAX1531) mall Input and Output Capacitors
· Timed Reset Output
· Uncommitted Overcurrent Protection (MAX1531)
· Soft-Start for All Regulators
· Programmable Input Undervoltage Comparator
· Programmable Startup Sequencing

The MAX1530/MAX1531 multiple-output power-supply ontrollers generate all the supply rails for thin-film transistor TFT) liquid-crystal display (LCD) monitors. Both evices include a high-efficiency, fixed-frequency, tep-down regulator. The low-cost, all N-channel, synchronous opology enables operation with efficiency as igh as 93%. High-frequency operation allows the use f small inductors and capacitors, resulting in a compact olution. The MAX1530 includes three linear regulatorcontrollers and the MAX1531 includes five linearregulator controllers for supplying logic and LCD biasvoltages. A programmable startup sequence enableseasy control of the regulators.

The MAX1530/MAX1531 include soft-start functions tolimit inrush current during startup. An internal stepdownconverter current-limit function and a versatileovercurrent shutdown protect the power supplies againstfault conditions. The MAX1530/MAX1531 use a currentmodecontrol architecture, providing fast load transientresponse and easy compensation. An internal linearregulator provides MOSFET gate drive and can beused to power small external loads.

The MAX1530/MAX1531 can operate from inputs ashigh as 28V and are well suited for LCD monitor and TVapplications running directly from AC/DC wall adapters.

Both devices are available in a small (5mm x 5mm),ultra-thin (0.8mm), 32-pin QFN package and operateover the -40 to +85 temperature range.