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LTC4244-1_15 Datasheet, PDF (1/28 Pages) Linear Technology – Rugged, CompactPCI Bus Hot Swap Controllers | |||
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LTC4244/LTC4244-1
Rugged, CompactPCI Bus
Hot Swap Controllers
FEATURES
DESCRIPTIO
s Controls â12V, 3.3V, 5V and 12V Supplies
s ±14.4V Absolute Maximum Rating for 12VIN
and â12VIN Input Pins
s Insensitive to Supply Voltage Transients
s Adjustable Foldback Current Limit with Circuit Breaker
s LOCAL_PCI_RST# Logic On-Chip
s PRECHARGE Output Biases I/O Pins During Card
Insertion and Extraction
s LTC4244-1 Designed for Applications without â12V
s Available in 20-Lead Narrow SSOP Package
U
APPLICATIO S
s Hot Board Insertion into CompactPCI Bus
, 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.
The LTC®4244/LTC4244-1 are Hot SwapTM controllers that
allow a board to be safely inserted into and removed from
a CompactPCITM bus slot. External N-channel transistors
control the 5V and 3.3V supplies while on-chip switches
control the ±12V supplies. The 3.3V and 5V supplies can
be ramped up at an adjustable rate. Electronic circuit
breakers protect all four supplies against overcurrent
faults. After the power-up cycle is complete, the TIMER pin
capacitor serves as auxiliary VCC allowing the LTC4244/
LTC4244-1 to function without interruption in the pres-
ence of voltage spikes on the 12VIN supply. The PWRGD
output indicates when all four supplies are within toler-
ance. The OFF/ON pin is used to cycle board power or reset
the circuit breaker. The PRECHARGE output can be used
to bias the bus I/O pins during card insertion and extrac-
tion. PCI_RST# is combined on-chip with HEALTHY# in
order to generate LOCAL_PCI_RST#.
TYPICAL APPLICATIO
5V
LONG 5V
3.3V
LONG 3.3V
12V
â12V
BD_SEL#
LONG V(I/O)
HEALTHY#
PCI_RST#
GROUND
I/O PIN 1
â¢â¢â¢
I/O PIN 128
C8
0.01µF PER
POWER PIN
C9
0.01µF PER
POWER PIN
5VIN
C6
0.01µF
R22
2.7â¦
R21
1.8â¦
C7
0.01µF
3.3VIN
R1
0.005â¦
Z3
Z4
Q1
IRF7457
R3
10â¦
R2
Q2
0.007⦠IRF7457
R4
10â¦
+
CLOAD(5VOUT)
+
CLOAD(3.3VOUT)
C1
R5 0.33µF
1k
VOUT
5V
5A
VOUT
3.3V
7A
Z1
R17
10k
R15
1â¦
C4
0.01µF
I/O DATA LINE 1
I/O DATA LINE 128
Z2
R20
1.2k
R16
1â¦
C5
0.01µF
â¢â¢â¢
R19 1k
R18 10k
3.3VIN
12VIN
VEEIN
3.3VSENSE GATE 3.3VOUT 5VIN
5VSENSE
OFF/ON
FAULT
LTC4244
5VOUT
12VOUT +
VEEOUT
CLOAD(12VOUT)
CLOAD(VEEOUT)
VOUT
12V
500mA
VEEOUT
â12V
100mA
PWRGD
RESETIN
GND PRECHARGE
C3 4.7nF
TIMER
C2
0.082µF
DRIVE RESETOUT
LOCAL_PCI_RST#
R9 24â¦
R8 1k
R6
10k VOUT
3.3V
R13
10â¦
R10 18â¦
R11
10k
R12
10k
Q3 R7 12â¦
1V MMBT2222A
±10%
R14
10â¦
â¢â¢â¢
VIN
3.3V
RESET#
I/O #1
PCI
BRIDGE
I/O #128 CHIP
Z1, Z2: SMAJ12A Z3, Z4: SMAJ5.0A
4244 F01
Figure 1. Typical Compact PCI Application
42441f
1
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