SMH4804 Datasheet, PDF (10/41 Pages) Summit Microelectronics, Inc. – -48V Programmable Hot Swap Sequencing Power Controller

Pin Descriptions
SMH4804
–
PIN DESCRIPTIONS
Table 1 provides the type, name, and description of the SMH4804 pins. Pin numbers are provided for both the
28-pin SOIC and 48-pin TQFP packages.
Pin Number Pin Number
(28-Pin SOIC) (48-Pin TQFP)
1
44
2
46
3
48
4
1
5
2
6
3
7
5
8
7
9
9
Pin Type
(I/O)
Pin Name
Description
I
DRAIN SENSE The DRAIN SENSE input monitors the voltage at the
drain of the external power MOSFET switch with
respect to VSS. An internal 10µA source pulls the
DRAIN SENSE signal towards the 5V reference level.
DRAIN SENSE must be held below 2.5V to enable the
PG[4:1] outputs.
I
A0
The A0 input works in conjunction with the A1 and A2
inputs. Together these inputs are used for decoding
multiple devices on the serial bus. The A0 input has an
internal 50KΩ pull-up to 5V.
O
VGATE
The VGATE output activates an external power
MOSFET switch. This signal supplies a constant
current output (100µA typical), which allows easy
adjustment of the MOSFET to turn on slew rate.
I
EN/TS
The Enable/Temperature Sense input is the master
enable input. If EN/TS is less than 2.5V, VGATE is
disabled. This pin has an internal 200KΩ pull-up to 5V.
I
PD1#
The PD1# pin works in conjunction with the PD2# pin
to optionally enable VGATE and the PG[4:1]outputs
when they are at V_SS. This pin has an internal 50KΩ
pull-up to 5V.
I
PD2#
The PD2# pin works in conjunction with the PD1# pin
to optionally enable VGATE and the PG[4:1]# outputs
when they are at V_SS. This pin has an internal 50KΩ
pull-up to 5V.
O
FAULT#
FAULT# is an open-drain, active-low output that
indicates the fault status of the device.
I
RESET#
The RESET# pin is used to clear latched fault
conditions. When this pin is asserted, the VGATE and
PG[4:1]# outputs are disabled. Refer to the section on
Circuit Breaker Operation for more information. This
pin has an internal 50KΩ pull-up to 5V.
I/O
SDA
SDA is the bidirectional serial data I/O port. This pin
has an internal 50KΩ pull-up to 5V.
Table 1. SMH4804 Pin Descriptions
10
2050 3.7 10/30/02
Summit Microelectronics