
Summit Microelectronics
INTRODUCTION
The SMH4802 is designed to control in-rush current during hot swapping of plug-in cards operating in a distributed power environment. The device drives an external power MOSFET switch that connects the supply to the load and protects against over-current conditions that might disrupt the host supply. It also provides undervoltage and over-voltage monitoring of the host power supply. When the source and drain voltages of the external MOSFETs are within specification it will provide a Power Good logic output that can be used to enable a DC/DC converter. Additional features of the device include: temperature sense or master enable input, a 5V reference output for expanding monitor functions, and duty-cycle or latched over-current protection modes. An internal Shunt regulator allows a wide supply range. The SMH4802 -48V Hot-Swap Controller also features a simple software I2C Power On/Off Interface for remote power control applications.
FEATURES & APPLICATIONS
● Soft Start Power Supply
● Live Insertion into a -48V backplane
● Programmable Control of a DC/DC Converter
♦ I2C Power On/Off Control
● Highly Programmable Circuit Breaker
♦ Active In-rush Current Limiting
♦ Over-current Filter Circuit Breaker Immunity to Voltage Steps and Current Spikes
● Programmable Forced Shutdown Timer
● Internal Shunt Regulator Allows a Wide Supply Range
● 14-pin SOIC packages
APPLICATIONS
● -48V Power Distribution
♦ Telecom Line Cards
♦ Central Office Switching
♦ High Availability Servers
♦ Hot Board Insertion