INTRODUCTION
The SMH4804 is a user-programmable -48V power supply controller designed to control the hot-swapping of plug-in cards and to sequence supplies in a distributed power environment. The SMH4804 drives an external power MOSFET switch that connects the bus side supply to the card side load and controls in-rush current while providing both current regulation and over-current protection. When the source and drain voltages of the external MOSFET are within specification, the SMH4804 asserts four PG[4:1]# power-good logic outputs either simultaneously or sequenced at programmable intervals to enable DC-DC converters to distribute card side power.

Features:
• Soft Starts Main Power Supply on Card Insertion or System Power Up
• In-Rush Current Limiting
• Master Enable to Allow System Control of Power Up or Down
• Programmable Independent Control of up to 4 DC/DC Converters via 4 Power Good Signals, PG[4:1]#
• Highly Programmable Circuit Breaker Level and Mode
    – Programmable Quick-Trip™ Value, Current Limiting, Duty Cycle Times, and Over-Current Filter
• Programmable Host Voltage Fault Monitoring
– Programmable UV/OV Filter and UV Hysteresis
• Programmable Fault Mode: Latched or Duty Cycle
• Internal Shunt Regulator Allows for a Wide Supply Range (typically -32 to -72 Volts)
• I2C 2-Wire Serial Bus Interface for Programming, Power On/Off and Operational Status

Applications:
• Telecom Hot-Swap Card
• Distributed Power Architectures
• Power-on LAN, IEEE 802.3