SMH4802
SMH4802 is Programmable -48V Hot-Swap Controller manufactured by Summit Microelectronics.
Features
& APPLICATIONS l Soft Start Power Supply l Live Insertion into a -48V backplane l Programmable Control of a DC/DC Converter w I2C Power On/Off Control l Highly Programmable Circuit Breaker w Active In-rush Current Limiting w Over-current Filter Circuit Breaker Immunity to Voltage Steps and Current Spikes l Programmable Forced Shutdown Timer l Internal Shunt Regulator Allows a Wide Supply Range l 14-pin SOIC and 16-pin SSOP packages APPLICATIONS l -48V Power Distribution w w w w Tele Line Cards Central Office Switching High Availability Servers Hot Board Insertion
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. Programming of configuration, control and calibration values by the user can be simplified with the SMX3200 interface adapter and a windows based GUI supplied by Summit.
SIMPLIFIED APPLICATION DRAWING
- 48V Ret
SDA I2C Header
UV PG#
V+
Out+
On/ DC/DC Off V- Out-
FS#
EN/TS VSS
CBSENSE VGATE
6 2
DRAIN SENSE 5VREF
1 11
- 48V A
2062 SAD
- 48V B
Figure 1. The drawing illustrates the SMH4802 in...
