LTC1644_15 Datasheet, PDF (1/24 Pages) Linear Technology – CompactPCI Bus Hot Swap Controller

FEATURES
s _{Allows Safe Board Insertion and Removal from a}
Live, CompactPCI^TM Bus
s _{Controls –12V, 3.3V, 5V and 12V Supplies}
s _{Adjustable Foldback Current Limit with Circuit}
Breaker
s _{Dual-Level Circuit Breakers Protect 5V and 3.3V}
Supplies from Overcurrent and Short-Circuit Faults
s _{LOCAL_PCI_RST# Logic On-Chip}
s _{PRECHARGE Output Biases I/O Pins During Card}
Insertion and Extraction
s _{Adjustable Supply Voltage Power-Up Rate}
U
APPLICATIO S
s _{Hot Board Insertion into CompactPCI Bus}
LTC1644
CompactPCI Bus
Hot Swap Controller
DESCRIPTIO
The LTC^®1644 is a Hot Swap^TM controller that allows a board
to be safely inserted and removed from a CompactPCI bus
slot. External N-channel transistors control the 3.3V/5V
supplies, while on-chip switches control the
–12V and 12V supplies. The 3.3V and 5V supplies can be
ramped up at a programmable rate. Electronic circuit break-
ers 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 PRECHARGE output
can be used to bias the bus I/O pins during card insertion
and extraction. PCI_RST# is combined on-chip with
HEALTHY# in order to generate LOCAL_PCI_RST#.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
CompactPCI is a trademark of the PCI Industrial Computer Manufacturers Group.
TYPICAL APPLICATIO
5V
LONG 5V
3.3V
LONG 3.3V
12V
–12V
BD_SEL#
HEALTHY#
PCI_RST#
GROUND
I/O PIN 1
I/O PIN 128
PCB EDGE
BACKPLANE BACKPLANE
CONNECTOR CONNECTOR
C8
0.1µF
PER 10
POWER
PINS
C9
0.1µF
PER 10
POWER
PINS
R22 2.74Ω
C6
0.01µF
R21 1.74Ω
C7
0.01µF
3V_IN*
Z3
5V_IN*
R1
0.005Ω
Q1
IRF7413
Z4
17
R3
10Ω
16
15
18
R2
0.007Ω
Q2
IRF7413
+
C_LOAD(5VOUT)
+
C1 ^CLOAD(3VOUT)
R4
10Ω
R5 _0.047µF
1k
13
14
3
5V_OUT
5V AT 5.7A
3V_OUT
3.3V AT 8A
Z1
Z2
5V_IN
EARLY V(I/O)
R17
2k
R20 1.2k
3V_IN
1
12V_IN
2
V_EEIN
R19
1k ₅
OFF/ON
6
FAULT
R18
2k ₇
PWRGD
9
RESETIN
3V_SENSE GATE 3V_OUT 5V_IN
LTC1644
20-PIN SSOP
5V_SENSE
5V_OUT
20
12V_OUT
+
C_LOAD(12VOUT)
19
V_EEOUT
C_LOAD(VEEOUT)
12V_OUT
12V AT 500mA
V_EEOUT
–12V AT 100mA
4
TIMER
10
RESETOUT
C2
0.1µF
R6
2k
3V_OUT
R15
1Ω
C4
0.01µF
R16
1Ω
C5
0.01µF
I/O DATA LINE 1
R13 10Ω
GND PRECHARGE
8
12
R10
18Ω 5%
R11
51k
C3 4.7nF
DRIVE
11
R9
24Ω
R8 1k
R12
51k
1V
±10%
Q3
R7
MMBT2222A 12Ω
I/O DATA LINE 128
R14 10Ω
Z1, Z2: SMAJ12CA Z3, Z4: 1PMT5.0AT3 *5V_IN AND 3V_IN MAY BE USED AS SOURCES OF EARLY POWER
3V_IN
RESET#
I/O #1
I/O #128
1644 F01
PCI
BRIDGE
CHIP
Figure 1
1644f
1