General Description
The MAX1964/MAX1965 power-supply controllers are designed to address cost-sensitive applications demanding voltage sequencing/tracking, 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 MAX1964 generates three positive outputs and the MAX1965 generates four positive outputs and one negative output to provide an inexpensive system power supply.

Features
♦ 4.5V to 28V Input Voltage Range
♦ Master DC-DC Step-Down Converter:
   Preset 3.3V or Adjustable (1.236V to 0.75 x VIN)
   Output Voltage
   Fixed Frequency (200kHz) PWM Controller
   No Current-Sense Resistor
   Adjustable Current Limit
   95% Efficient
   Soft-Start
♦ Two (MAX1964)/Four (MAX1965) Analog Gain
   Blocks:
   Positive Analog Blocks Drive Low-Cost PNP
   Pass Transistors to Build Positive Linear
   Regulators
   Negative Analog Block (MAX1965) Drives a
   Low-Cost NPN Pass Transistor to Build a
   Negative Linear Regulator
♦ Power-Good Indicator
♦ Voltage Sequencing (MAX1964) or Tracking
   (MAX1965)

Applications
   xDSL, Cable, and ISDN Modems
   Set-Top Boxes
   Wireless Local Loop