SMH4802_09 Datasheet, PDF (4/19 Pages) Summit Microelectronics, Inc. – Programmable -48V Hot-Swap Controller with Forced Shut Down

PIN DESCRIPTIONS (Continued)
SMH4802
Preliminary Information
Pin No. Type Pin Name
Pin Description
9
I
The OV pin is used as an under-voltage supply monitor, typically in conjunction
OV with an external resistor ladder. VGATE will be disabled if OV is greater than
2.5V. A filter delay is also available on the OV input.
10
I
The Forced Shutdown pin is an active low input that causes VGATE and the PG#
output to be shut down at any time after an internal hold-off timer has expired.
FS# The hold-off timer allows supervisory circuits on the secondary side (which are
not powered up initially) to control shut down of the SMH4802 via an opto-
isolator. This input has no pullup resistor.
11
O
5VREF
This is a 5V output reference voltage that may be used to expand the logic input
functions on the SMH4802. The reference output is with respect to V_SS.
12
O
PG#
PG# is an open-drain, active-low output with no internal pullup resistor. It can be
used to switch a Ioad or enable a DC/DC converter. PG# is enabled after 3
events: VGATE reaches V_DD - V_GT , the Drain Sense voltage is less than 2.5V,
and the programmed delay time has expired. Voltage on this pin cannot exceed
12V as referenced to V_SS.
13
nc
nc
No connection
14 PWR
V_DD is the positive supply connection. An internal shunt regulator connected
V_DD
between V_DD and V_SS develops approximately 12V that supplies the SMH4802.
A resistor Must be placed in series with the V_DD pin to limit the regulator current
(R_D in the application illustrations).
Note: Pin numbers reflect the 14 Pin SOIC package.
2062 Pin Table B
4
2062 2.3 6/19/03
SUMMIT MICROELECTRONICS, Inc.