LTC4245CUHF
1
DESCRIPTION
Demonstration circuit 985 showcases
the LTC
®
4245 Hot Swap™ controller
with I
2
C™ compatible monitoring in a
CompactPCI™ (CPCI) application. The
LTC4245 resides on the plug-in board,
DC985A-A, which carries a female CPCI
connector. This board plugs into the
male connector on the backplane
board, DC985A-B. The plug-in board
also carries the four n-FET switches
and sense resistors required for hot
swap. LEDs provide visual indication
of the important signals and volt-
ages.
The board can be configured to work
in a PCI Express™ application by ad-
justing a few jumpers. To access the
powerful monitoring features of the
LTC4245, the I
2
C port on the back-
plane board must be connected to a
DC590 board (available separately).
The LTC4245 can then be controlled
with evaluation software running on a
host PC.
Design files for this circuit board
are available. Call the LTC factory.
and LTC are registered trademarks of Linear Technology
Corporation. Hot Swap and QuickEval are trademarks of Linear
Technology Corporation. All other trademarks are the property
of their respective owners.
PERFORMANCE SUMMARY
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
V
IN
Input Supply Range
+12V IN
+5V IN
+3.3V IN
-12V IN
MOSFET Q1-Q4 On, TVS Z1-Z4 Off
CFG Jumper, JP4, at LOW or FLOAT
CFG Jumper, JP4, at HIGH
CFG Jumper, JP4, at LOW
CFG Jumper, JP4, at FLOAT or HIGH
10.8
4.5
2.9
2.9
-10.8
0
12
5
3.3
3.3
-12
15
6
6
6
-15
-15
V
V
V
V
V
V
I
OUT,CB
Circuit Breaker Trip Current
+12V OUT
+5V OUT
+3.3V OUT
-12V OUT
After Start-Up
R1 = 8m
Ω, 1%
R2 = 3.5m
Ω, 1%
R3 = 2.5m
Ω, 1%
R4 = 40m
Ω, 1%
5.5
6.4
8.9
0.99
6.25
7.1
10
1.25
6.9
7.9
11.1
1.52
A
A
A
A
QUICK START PROCEDURE
1.
Verify that the jumpers are set as
follows:
Backplane board:
JP1 BD_SEL#: LOW;
JP2 PCI_RST#: HIGH
Plug-in board:
JP3 ON CONFIG: AUTO;
JP5 PGI: HIGH; JP4 CFG: LOW if us-
ing all four supplies, FLOAT if us-
ing 12V, 5V and 3.3V, HIGH if using
12V, and two 3.3V.
DEMO CIRCUIT 985
QUICK START GUIDE
LTC4245CUHF
Multiple Supply Hot Swap Controller
with I
2
C Compatible Monitoring
