MAX1865

19-2030; Rev 0; 4/01 EVAALVUAAILTAIOBNLEKIT xDSL/Cable Modem Triple/Quintuple Output Power Supplies MAX1864/MAX1865 General Description The MAX1864/MAX1865 power-supply controllers are designed to address cost-conscious applications such as cable modem Consumer Premise Equipment (CPE), xDSL CPE, and set-top boxes. Operating off a low-cost, unregulated DC supply (such as a wall adapter output), the MAX1864 generates three positive outputs, and the MAX1865 generates four positive outputs and one negative output to provide a cost-effective system power supply. The MAX1864 includes a current-mode synchronous step-down controller and two positive regulator gain blocks. The MAX1865 has one additional positive gain block and one negative regulator gain block. The main synchronous step-down controller generates a high-current output that is preset to 3.3V or adjustable from 1.236V to 0.8 ✕ VIN with an external resistivedivider. The 100kHz/200kHz operating frequency allows the use of low-...