LTC4240_15 Datasheet, PDF (1/28 Pages) Linear Technology – CompactPCI Hot Swap Controller with I2C Compatible Interface

LTC4240
CompactPCI Hot Swap
Controller with I²C Compatible Interface
FEATURES
s _{Allows Safe Board Insertion and Removal from a}
Live CompactPCI^TM Bus
s _I²_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^® _{Enable Output}
s _{Status LED Driver}
s _{User Programmable Supply Voltage Power-Up Rate}
s _{Registers Individual Supply Faults}
s _{Available in a 28-UPin Narrow SSOP Package}
APPLICATIO S
s _{Hot Board Insertion into CompactPCI Bus}
s _{Electronic Circuit Breaker}
, 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.
I²C is a trademark of Philips Electronics N.V.
DESCRIPTIO
The LTC^®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 I²C 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 I²C 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 I²C 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.
TYPICAL APPLICATIO
MEDIUM 5V
LONG 5V
MEDIUM 3.3V
LONG 3.3V
LONG V(I/O)
SCL
SDA
12V
–12V
BD_SEL#
HEALTHY#
PCI_RST#
GROUND
CompactPCI
BACKPLANE
CONNECTOR
(MALE)
CompactPCI
BACKPLANE
CONNECTOR
(FEMALE)
C11
10nF
5V_IN
R22, 2.74Ω
3V_IN
R21, 1.74Ω
C10
10nF
R19
2.55k
1%
Z4
C7
0.01µF
PER
PIN
C8
0.01µF
PER
PIN
R20
C9
1.91k
10nF _R12 1%
10k
R28, 200Ω
R25, 1.2k
Z3
R1
0.005Ω
Q1
Si7880DP
R3
10Ω
R2
0.007Ω
Q2
Si7880DP
R4
10Ω
+
C_LOAD (5V_OUT)
+
5V_OUT
5V AT 5A
3V_OUT
3.3V AT 7.6A
C1
R5 _0.047µF
1k
C_LOAD (3V_OUT)
5V_IN
3V_IN
ADDRIN
SCL
SDA
PRSNT2#
PRSNT1#
12V_IN
3V_SENSE GATE 3V_OUT 5V_IN
5V_SENSE
5V_OUT
DGND
LED
12V_OUT
R10
100Ω
+
12V_OUT
12V AT 500mA
C_LOAD (12V_OUT)
Z1
R13
10Ω
C4
0.01µF
5V_IN
R17, 1.2k
V_EEIN
R18
1k
OFF/ON
EARLY
V(I/O) _{R29 R15}
R16
FAULT
10Ω 2k
10k
PWRGD
R30
R14
Z2 ^1k
10Ω
RESETIN
C6
GND
0.01µF
C5
0.01µF
Z1, Z2: SMAJ12CA
Z3, Z4: IPMT5.0AT3
PRECHARGE
R11
18Ω
LTC4240
C3, 4.7nF
V_EEOUT
TIMER
BE
RESETOUT
DRIVE
R8, 1k
R9
24Ω
R7, 12Ω
Q3
MMBT2222A
C2 ₊
0.1µF
R6
10k
V_EEOUT
–12V AT 100mA
C_LOAD (V_EEOUT)
TO
QUICKSWITCH^®
ENABLE
3V_OUT
LOCAL_PCI_RST#
3V_IN
TO PCI BRIDGE
DEVICE OR
EQUIVALENT
4240 TA01
4240f
1