SMH4812_09 Datasheet, PDF (2/18 Pages) Summit Microelectronics, Inc. – Distributed Power Hot-Swap Controller

SMH4812
Preliminary
DESCRIPTION
The SMH4812 is designed to control hot swapping of plug-
in cards operating from a single supply, which can have an
output range from 20V to 500V. The SMH4812 hot-swap
controller provides under-voltage and over-voltage moni-
toring of the host power supply, it drives an external power
MOSFET switch that connects the supply to the load, and
it protects against over-current conditions that might dis-
rupt the host supply. When the input and output voltages
to the SMH4812 controller are within specification it pro-
vides a Power Good logic output that may be used to
enable a DC-DC converter. Additional features of the
device 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 or latched over-current protection
modes. All of these features can be programmed by the
factory according to the user's requirements.
FUNCTIONAL BLOCK DIAGRAM
VDD 16
12VREF
DRAIN
SENSE ¹
EN/TS 3
PD1# 4
PD2# 5
UV 9
OV 10
50kΩ
50kΩ
50kΩ
+
–
+
–
+
–
5V
12V
VSS 8
2.5V
+
–
FILTER
ENPG
14
PROGRAMM-
ABLE
SHUTDOWN
TIMER
13 FS#
12 2.5VREF
11 5.0VREF
PROGRAMM-
ABLE
DELAY
15 PG#
50kΩ
VGATE
SENSE
2 VGATE
CBSENSE 7
2
PROGRAMM-
ABLE
DELAY
+
–
50mV
+
Programmable
–
Quick Response
Ref. Voltage
DUTY
CYCLE
TIMER
2055 4.1 03/27/09
6 _FAULT#
2055 BD 3.0
SUMMIT MICROELECTRONICS, Inc.