?/DIV>
4240 is a Hot Swap
TM
controller that allows a board
to be safely inserted and removed from a live CompactPCI
bus slot. The LTC4240 has a built-in 2-wire I
2
C compatible
interface to allow software control and monitoring of
device function and power supply status. Two external
N-channel transistors control the 3.3V and 5V supplies,
while two internal switches control the 12V and 12V
supplies. Electronic circuit breakers protect all four supplies
against overcurrent faults. The PWRGD output indicates
when all of the supply voltages are within tolerance. The
OFF/ON pin is used to cycle the board power or reset the
circuit breaker. The I
2
C interface allows the user to turn the
device off or on, set RESETOUT, turn on the status LED
driver and ignore 12V, 12V faults. It also allows the user
to read the status of the FAULT, RESETIN, RESETOUT,
PWRGD, PRSNT1# and PRSNT2# pins. Under a fault
condition, the I
2
C interface can also be used to determine
which of the four supplies generated the fault. The LTC4240
is available in a 28-pin narrow SSOP package.
s
Hot Board Insertion into CompactPCI Bus
s
Electronic Circuit Breaker
s
Allows Safe Board Insertion and Removal from a
Live CompactPCI
TM
Bus
s
I
2
C
TM
Compatible 2-Wire Interface
s
PRECHARGE Output Biases I/O Pins During Card
Insertion and Extraction
s
Controls 3.3V, 5V, 12V and 12V Supplies
s
Foldback Current Limit with Circuit Breaker
s
LOCAL_PCI_RST# Logic On-Board
s
QuickSwitch
?/DIV>
Enable Output
s
Status LED Driver
s
User Programmable Supply Voltage Power-Up Rate
s
Registers Individual Supply Faults
s
Available in a 28-Pin Narrow SSOP Package
CompactPCI Hot Swap
Controller with I
2
C Compatible Interface
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
QuickSwitch is a registered trademark of Quality Semiconductor Corp.
CompactPCI is a trademark of the PCI Industrial Computer Manufacturers Group.
I
2
C is a trademark of Philips Electronics N.V.
C5
0.01礔
C1
0.047礔
C4
0.01礔
GND
12V
IN
V
EEIN
OFF/ON
FAULT
PWRGD
RESETIN
3V
IN
3V
IN
5V
IN
3V
SENSE
3V
OUT
5V
IN
LTC4240
PRECHARGE
DRIVE
5V
OUT
5V
SENSE
GATE
12V
OUT
V
EEOUT
TIMER
RESETOUT
EARLY
V(I/O)
R16
10k
R18
1k
R17, 1.2k
R3
10&
5V
IN
R4
10&
R15
2k
R30
1k
R29
10&
5V
OUT
5V AT 5A
3V
OUT
3.3V AT 7.6A
12V
OUT
12V AT 500mA
V
EEOUT
12V AT 100mA
4240 TA01
R11
18&
3V
IN
3V
OUT
R6
10k
R5
1k
R8, 1k
R7, 12&
C3, 4.7nF
R9
24&
R1
0.005&
Q1
Si7880DP
Q2
Si7880DP
R2
0.007&
C2
0.1礔
R13
10&
R14
10&
MEDIUM 5V
LONG 5V
MEDIUM 3.3V
LONG 3.3V
LONG V(I/O)
12V
12V
BD_SEL#
HEALTHY#
PCI_RST#
GROUND
TO PCI BRIDGE
DEVICE OR
EQUIVALENT
BE
DGND
LED
SCL
SDA
R19
2.55k
1%
R20
1.91k
1%
PRSNT2#
PRSNT1#
ADDRIN
SCL
SDA
C8
0.01礔
PER
PIN
C
LOAD
(5V
OUT
)
C
LOAD
(3V
OUT
)
C
LOAD
(12V
OUT
)
C
LOAD
(V
EEOUT
)
C7
0.01礔
PER
PIN
C6
0.01礔
5V
IN
Z4
Z1
Z2
Z1, Z2: SMAJ12CA
Z3, Z4: IPMT5.0AT3
Z3
CompactPCI
BACKPLANE
CONNECTOR
(FEMALE)
CompactPCI
BACKPLANE
CONNECTOR
(MALE)
LOCAL_PCI_RST#
R10
100&
TO
QUICKSWITCH
?/DIV>
ENABLE
Q3
MMBT2222A
R12
10k
R22, 2.74&
R21, 1.74&
R25, 1.2k
R28, 200&
+
+
+
C9
10nF
C10
10nF
C11
10nF