SUMMIT
MICROELECTRONICS, Inc.
Distributed Power Hot-Swap Controller
SMH4811A
Preliminary
FEATURES
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Supply Range ±20VDC to >±500VDC
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Versatile Card Insertion Detection Supports:
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Multi-length Pin Systems
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Card Injector Switch Sensing
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Programmable Debounce Periods
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Control Powering-on of DC/DC Converters
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Highly Programmable Host Voltage Monitoring
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Programmable Under- and Over-voltage
Detection
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Programmable UV Filter
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Programmable Power Good Delay for enabling
the DC/DC Converter
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Programmable Circuit Breaker Function
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Programmable Over-Current Filter
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Programmable Quick-Trip™ Circuit Breaker
Values
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2.5V and 5.0V reference outputs
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Easy Expansion of External Monitor
Functions
DESCRIPTION
The SMH4811A is designed to control hot swapping of
plug-in cards operating from a single supply ranging from
20V to 500V. It provides under-voltage and over-voltage
monitoring of the host power supply, drives an external
power MOSFET switch that connects the supply to the
load, and also protects against over-current conditions
that might disrupt the host supply. When the input and
output voltages to its controls are within specification, it
provides a Power Good logic output that may be used to
turn loads on (e.g., an isolated-output DC-DC converter,
or drive a LED status light). Additional features of the
SMH4811A include: temperature sense or master enable
input, 2.5V and 5V reference outputs for expanding moni-
tor functions, two Pin-Detect enable inputs for fault protec-
tion, and duty-cycle over-current protection.
SIMPLIFIED APPLICATION DRAWING
0V
Disable/Enable
VDD
Pin Detect
PD1#
ENPG
FAULT#
UV
SMH4811A
OV
PG#
DC/DC
Pin Detect
PD2#
VSS
CBSENSE VGATE 2.5VREF 5.0VREF
–48V
Characteristics subject to change without notice
2044 SAD 5.1
©SUMMIT MICROELECTRONICS, Inc., 2000 • 300 Orchard City Dr., Suite 131 • Campbell, CA 95008 • Phone 408-378-6461 • FAX 408-378-6586 • www.summitmicro.com
2044 6.1 2/8/01
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SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
