SUMMIT
MICROELECTRONICS, Inc.
S39421
Hot Swap Voltage Controller
FEATURES
• Full Voltage Control for Hot Swap Applications
– Card Insertion Detection
– Platform Voltage Detection
– Card Voltage Sequencing
– 5 Volt, 12 Volt and 3.3 Volt
• 12 Volt FET Enable Outputs
– Allows use of Low On-resistance N-Channel
FETS
• Card Reset Generation Based on Out of Spec
Voltages
– Host Reset
• Programmable Slew Rate Control [250V/Sec
Default Rate]
• Supports 5 Volt, 3.3 Volt and Mixed Voltage
Cards
• Integrated 1K Bit E
2
PROM Memory
• Data Download™ Mode [Simplifies
Downloading of Configuration Memory into
Interface ASIC or MCU]
DESCRIPTION
The S39421 is a fully integrated hot swap controller
intended for use on add-in cards that may be inserted into
or removed from powered-on host platforms. The S39421
performs a variety of tasks starting with the validation of
proper card insertion and the presence of “in-spec” volt-
ages at the host platform interface.
Once power is switched on, the S39421 continues to
monitor the back-end power to the add-in card and the
host power supply. If either the 5V or 3.3V supplies drop
below Vtrip the S39421 will immediately assert the RE-
SET outputs and power-down the add-in card.
In addition to the power control for the add-in card, the
S39421 provides status signals that can be employed by
the host and for the control of bus interface components.
The on board E
2
PROM can be used as configuration
memory for the individual card or as general purpose
memory. The proprietary DataDownload mode provides
a more direct interface to the E
2
PROM for simplified
access by the add-in card’s controller or ASIC.
FUNCTIONAL BLOCK DIAGRAM
W
R
_P
EL
ST
VS
H
ST
H
_R
ST
VCC5
EEPROM
Memory
Array
+
VCC3
-
+
CARD_5V
-
+
CARD_3V
-
+
-
Filter
PND1
DD
DO
CS
SK
DI
DRVREN
SGNL_VLD
CARD_V_VLD
ASSOCIATE
MEMBER
Sequencing
Logic
RESET
Timer
RESET
RESET
PND2
ISLEW
Slew Rate
Control
VGATE3
VGATE5
12
SUMMIT MICROELECTRONICS, Inc.
•
300 Orchard City Drive, Suite 131
•
Campbell, CA 95008
VC
C
2024 ILL2.1
•
Telephone 408-378-6461
•
Fax 408-378-6586
•
www.summitmicro.com
© SUMMIT MICROELECTRONICS, Inc. 1999
2024 9.0 8/8/00
1
Characteristics subject to change without notice
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
