LTC4244/LTC4244-1
Rugged, CompactPCI Bus
Hot Swap Controllers
FEATURES DESCRIPTIO
TM
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Controls 12V, 3.3V, 5V and 12V Supplies The LTC 4244/LTC4244-1 are Hot Swap controllers that
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14.4V Absolute Maximum Rating for 12V allow a board to be safely inserted into and removed from
IN
TM
and 12V Input Pins a CompactPCI bus slot. External N-channel transistors
IN
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Insensitive to Supply Voltage Transients control the 5V and 3.3V supplies while on-chip switches
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Adjustable Foldback Current Limit with Circuit Breaker control the 12V supplies. The 3.3V and 5V supplies can
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LOCAL_PCI_RST# Logic On-Chip be ramped up at an adjustable rate. Electronic circuit
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PRECHARGE Output Biases I/O Pins During Card breakers protect all four supplies against overcurrent
Insertion and Extraction faults. After the power-up cycle is complete, the TIMER pin
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LTC4244-1 Designed for Applications without 12V capacitor serves as auxiliary V allowing the LTC4244/
CC
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Available in 20-Lead Narrow SSOP Package LTC4244-1 to function without interruption in the pres-
ence of voltage spikes on the 12V supply. The PWRGD
IN
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output indicates when all four supplies are within toler-
APPLICATIO S
ance. The OFF/ON pin is used to cycle board power or reset
n Hot Board Insertion into CompactPCI Bus
the circuit breaker. The PRECHARGE output can be used
to bias the bus I/O pins during card insertion and extrac-
, LTC and LT are registered trademarks of Linear Technology Corporation.
tion. PCI_RST# is combined on-chip with HEALTHY# in
Hot Swap is a trademark of Linear Technology Corporation.
CompactPCI is a trademark of the PCI Industrial Computer Manufacturers Group. order to generate LOCAL_PCI_RST#.
TYPICAL APPLICATIO
C8 C9
0.01F PER 0.01F PER
R2 Q2
5V
IN
POWER PIN POWER PIN
0.007 IRF7457 V
OUT
5V 5V
+
R22
5A
C
2.7 R1 Q1 LOAD(5VOUT)
LONG 5V 0.005 IRF7457
V
3.3V OUT
IN
3.3V 3.3V
+
R21
7A
C
1.8 Z3
LOAD(3.3VOUT)
LONG 3.3V
R3 R4
C1
Z4
C6 C7 10
10
R5
0.33F
0.01F 0.01F
1k
Z1 Z2
3.3V 3.3V GATE 3.3V 5V 5V 5V
IN SENSE OUT IN SENSE OUT
V
OUT
12V 12V
12V IN OUT 12V
+
500mA
V
12V EEIN
C
LOAD(12VOUT)
R19 1k
OFF/ON V
BD_SEL# EEOUT
V
R20 12V
EEOUT
R18 10k LTC4244 C 100mA
1.2k LOAD(VEEOUT)
LONG V(I/O) FAULT
R17
10k
TIMER
PWRGD C2
HEALTHY#
0.082F
R6
PCI_RST# RESETIN
10k
V
OUT
GND PRECHARGE RESETOUT
DRIVE
3.3V
R15 R16 LOCAL_PCI_RST#
1 1 R9 24
C3 4.7nF
R8 1k
C4 C5
0.01F 0.01F
V
IN
GROUND
3.3V
Q3
R10 18 R7 12
R11 R12
R13
1V MMBT2222A
RESET#
10k 10k
10
I/O DATA LINE 1 10% I/O #1
I/O PIN 1
PCI
R14
BRIDGE
10
I/O DATA LINE 128 I/O #128
CHIP
I/O PIN 128
Z1, Z2: SMAJ12A Z3, Z4: SMAJ5.0A
4244 F01
Figure 1. Typical Compact PCI Application
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ULTC4244/LTC4244-1
UUW
ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO
(Notes 1, 2, 3)
Supply Voltages ORDER PART
TOP VIEW
NUMBER
12V ................................................................ 14.4V
IN
12V 1 20 12V
IN OUT
V .............................................................. 14.4V
EEIN V 2 19 V
EEIN
EEOUT
LTC4244CGN
Input Voltages (OFF/ON, RESETIN) ........0.3V to 13.5V
5V 3 18 3.3V
OUT
OUT
LTC4244CGN-1
Output Voltages (FAULT, PWRGD, RESETOUT)
TIMER 4 17 3.3V
IN
LTC4244IGN
...........................................................0.3V to 13.5V OFF/ON 5 16 3.3V
SENSE
LTC4244IGN-1
FAULT 6 15 GATE
Analog Voltages and Currents
PWRGD 7 14 5V
5V , DRIVE, 5V , 3.3V , 3.3V , 3.3V , 5V SENSE
OUT IN SENSE IN OUT SENSE
GND 8 13 5V
IN
...........................................................0.3V to 13.5V
RESETIN 9 12 PRECHARGE
PRECHARGE, GATE ....................................... 20mA
RESETOUT 10 11 DRIVE
V ................................................ 14.4V to 0.3V
EEOUT
GN PACKAGE
TIMER, 12V ...........................................0.3V to 14.4V
OUT
20-LEAD PLASTIC SSOP
Operation Temperature Range
T = 140C, = 135C/ W
JMAX JA
LTC4244C/LTC4244C-1........................... 0C to 70C
LTC4244I/LTC4244I-1 ........................ 40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges.
Storage Temperature Range ................. 65C to 150C
Lead Temperature (Soldering, 10 sec).................. 300C
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25C. V = 12V, V = 12V, V = 3.3V, V = 5V, unless
A 12VIN EEIN 3.3VIN 5VIN
otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I V Supply Current OFF/ON = 0V l 410 mA
DD 12VIN
V Undervoltage Lockout 12V , Ramping Down l 8 9 10 V
LKO IN
5V , Ramping Down l 4 4.25 4.5 V
IN
3.3V , Ramping Down l 2.25 2.5 2.75 V
IN
, Ramping Up (LTC4244 Only) l 8.25 9.25 10.25 V
V
EEIN
TIMER, Ramping Down, V = 6V l 8.25 9.25 10.25 V
12VIN
V Foldback Current Limit Voltage V = (V V ), V = 0V, TIMER = 0V l 11 16 21 mV
FB FB 5VIN 5VSENSE 5VOUT
V = (V V ), V = 3V, TIMER = 0V l 46 51 56 mV
FB 5VIN 5VSENSE 5VOUT
V = (V V ), V = 0V, TIMER = 0V l 11 16 21 mV
FB 3.3VIN 3.3VSENSE 3.3VOUT
V = (V V ), V = 2V, TIMER = 0V l 46 51 56 mV
FB 3.3VIN 3.3VSENSE 3.3VOUT
V Circuit Breaker Trip Voltage V = (V V ), TIMER = FLOAT l 45 52 57 mV
CB CB 5VIN 5VSENSE
V = (V V ), TIMER = FLOAT l 45 52 57 mV
CB 3.3VIN 3.3VSENSE
t Overcurrent Fault Response Time (V V ) = 100mV, TIMER = FLOAT l 17 25 35 s
OC 5VIN 5VSENSE
(V V ) = 100mV, TIMER = FLOAT l 17 25 35 s
3.3VIN 3.3VSENSE
I GATE Pin Output Current OFF/ON = 0V, V = 2V, TIMER = 0V l 20 67 100 A
GATE(UP) GATE
I V = 5V, OFF/ON = 4V l 20 60 100 A
GATE(DN) GATE
I OFF/ON = 0V, V = 2V, TIMER = FLOAT, FAULT = 0V l 4 8 16 mA
GATE(FAULT) GATE
V External Gate Voltage V = (V V ), I = 1A l 0.6 1 V
GATE GATE 12VIN GATE GATE
V Internal Switch Voltage Drop V = (V V ), I = 500mA l 225 600 mV
12V 12V 12VIN 12VOUT
V V = (V V ), I = 100mA l 110 250 mV
VEE VEE EEOUT EEIN EE
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