SMH4811A
Preliminary
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.
PIN CONFIGURATION
DRAIN SENSE
VGATE
EN/TS
PD1#
PD2#
FAULT#
CBSENSE
V
SS
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
DD
PG#
ENPG
NC
2.5V
REF
5V
REF
OV
UV
2044 PCon 5.1
FUNCTIONAL BLOCK DIAGRAM
ENPG
14
VDD
16
12VREF
12
2.5VREF
+
DRAIN
1
SENSE
50kΩ
200kΩ
50kΩ
To EN/TS
To PD1#
To PD2#
–
11
5.0VREF
50kΩ
PROGRAMM-
ABLE
DELAY
5V
12V
2.5VREF
VSS
8
15
PG#
UV
9
–
2.5VREF
w/prog
hysteresis
2.5VREF
Reg6[3]
OV
10
EN/TS
3
2.5VREF
PD1#
4
PD2#
5
PROGRAMM-
ABLE
DELAY
50mV
CBSENSE
7
2
+
+
–
Reg6[2]
OV/UV Filter
t
UV/OVF
Reg4[2:1]
VGATE
SENSE
PD Timer
t
PD
2
VGATE
+
–
Reg9[1:0]
+
–
6
FAULT#
+
Programmable
Quick Response
Ref. Voltage
DUTY
CYCLE
TIMER
–
2044 6.6
03/27/09
SUMMIT MICROELECTRONICS, Inc.
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
