LTC4241
PCI-Bus with 3.3V Auxiliary
Hot Swap Controller
FEATURES
DESCRIPTIO
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Allows Safe Board Insertion and Removal from a The LTC 4241 is a Hot Swap controller that allows a board
Live PCI Slot to be safely inserted and removed from a live PCI-bus slot.
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Controls 3.3V, 5V, 12V, 12V and 3.3V Auxiliary It has a primary controller that controls the four PCI
Supplies supplies and an independent auxiliary controller to control
TM
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Independent 3.3V Auxiliary Supply Hot Swap the 3.3V auxiliary supply. External N-channel transistors
Controller are used to control the 3.3V, 5V and 3.3V auxiliary supplies
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Adjustable Foldback Current Limit with Circuit while on-chip switches control the 12V and 12V supplies.
Breaker The 3.3V, 5V and 3.3V auxiliary supplies can be ramped up
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Adjustable Supply Voltage Power-Up Rate at an adjustable rate. Electronic circuit breakers protect all
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High Side Drive for External N-Channel FETs five supplies against overcurrent faults. The foldback
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12V and 12V On-Chip Switches current limit feature reduces current spikes and power
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Fault and Power Good Outputs dissipation when shorts occur. The PWRGD output of the
U
primary controller indicates when all four PCI supplies are
APPLICATIO S
within tolerance. The FAULT output indicates an overcurrent
condition for any of the five supplies.
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PCI-Based Servers
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Computer Systems The LTC4241 is available in the 20-pin narrow SSOP
package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
GND
R1 Q1
5V
0.007 IRF7413
5A
R4
R2
Q2
3.3V
0.005 10
IRF7413
7.6A
R3 R5
Q3
3.3V
AUX
10
0.07
Si2306DS
500mA
SYSTEM
POWER
SUPPLY
C3
R7
R6
10nF
10 100
C1
0.047F
11 10 9 13 14 15 3 17 16 18
AUXIN AUXSENSE AUXGATE 3V 3V GATE 3V 5V 5V 5V
IN SENSE OUT IN SENSE OUT
8
GND
1
12V
12V
IN
2
20 500mA
V
12V
EEIN OUT
12
12V
AUXON
5 19 100mA
LTC4241
ON V
EEOUT
R8 10k
6 4 BACKPLANE
PCI
FAULT TIMER
POWER CONNECTOR
C2
R9 10k
SYSTEM
0.1F
7
CONTROLLER
PWRGD
LOGIC
RESET
RESET
4241 F01
Figure 1. Hot Swappable PCI and 3.3V Auxiliary Supplies
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ULTC4241
UUW
ABSOLUTE AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
(Note 1)
ORDER PART
Supply Voltages
NUMBER
12V ................................................................... 14V
IN
V .................................................................. 14V
EEIN
LTC4241CGN
TOP VIEW
AUXIN ................................................................... 7V
LTC4241IGN
12V 1 20 12V
IN OUT
Input Voltage
V 2 19 V
EEIN EEOUT
ON ......................................................... 0.3V to 14V
3V 3 18 5V
OUT OUT
AUXON .................................................. 0.3V to 14V
TIMER 4 17 5V
IN
Output Voltages
ON 5 16 5V
SENSE
(FAULT, PWRGD) .................................. 0.3V to 14V
FAULT 6 15 GATE
Analog Voltages
PWRGD 7 14 3V
SENSE
TIMER, 3V , 3V , GATE,
IN SENSE
GND 8 13 3V
IN
5V , 5V .............................0.3V to (12V + 0.3V)
SENSE IN IN AUXGATE 9 12 AUXON
3V , 5V ........................................ 0.3V to 14V
AUXSENSE 10 11 AUXIN
OUT OUT
AUXSENSE ..........................0.3V to (AUXIN + 0.3V)
GN PACKAGE
V ................................................ 14V to + 0.3V
EEOUT 20-LEAD NARROW PLASTIC SSOP
T = 150 C, q = 135 C/W
JMAX JA
12V .................................................. 0.3V to 14V
OUT
AUXGATE ......................... Internally Limited (Note 3)
Operating Temperature Range
LTC4241CGN........................................... 0 C to 70 C
LTC4241IGN ........................................40 C to 85 C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Storage Temperature Range ..................65 C to 150 C
Lead Temperature (Soldering,10sec).................... 300 C
DC ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25 C. V = 12V, V = 12V, V = 3.3V, V = 5V,
A 12VIN VEEIN 3VIN 5VIN
V = 3.3V. (Note 2)
AUXIN
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I V Supply Current ON = V l 2.5 8 mA
DD 12VIN 12VIN
V Supply Current AUXON = V l 0.5 1.5 mA
AUXIN AUXIN
V Undervoltage Lockout, 12V l 6.5 9 10.8 V
LKO IN
Low-to-High Transition 3V l 2.25 2.50 2.75 V
IN
5V l 3.65 3.90 4.15 V
IN
AUXIN l 2.35 2.60 2.85 V
V Undervoltage Lockout Hysteresis 3V , 5V 20 mV
LKH IN IN
AUXIN 120 mV
V Current Limit Sense Voltage V = 0V l 5.5 9 14.5 mV
SENSE5(TH) 5VOUT
Threshold (V V )V > 4V l 40 55 70 mV
5VIN 5VSENSE 5VOUT
V Current Limit Sense Voltage V = 0V l 5.5 9 14.5 mV
SENSE3(TH) 3VOUT
Threshold (V V )V > 2V l 40 55 70 mV
3VIN 3VSENSE 3VOUT
t Circuit Breaker Trip Filter Time (V V ) = Step 0 to 100mV 17 m s
CB 5VIN 5VSENSE
(V V ) = Step 0 to 100mV 8 m s
AUXIN AUXSENSE
I GATE Pin Output Current ON High, FAULT High, V = GND l 20 60 100 m A
GATE GATE
ON Low, FAULT High, V = 5V 200 m A
GATE
ON High, FAULT Low, V = 5V 5 25 35 mA
GATE
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