4241 layout
LTC4241
1
sn4241 4241f
FEATURES
APPLICATIO S
U
DESCRIPTIO
U
TYPICAL APPLICATIO
U
s
Allows Safe Board Insertion and Removal from a
Live PCI Slot
s
Controls 3.3V, 5V, 12V, 12V and 3.3V Auxiliary
Supplies
s
Independent 3.3V Auxiliary Supply Hot Swap
TM
Controller
s
Adjustable Foldback Current Limit with Circuit
Breaker
s
Adjustable Supply Voltage Power-Up Rate
s
High Side Drive for External N-Channel FETs
s
12V and 12V On-Chip Switches
s
Fault and Power Good Outputs
PCI-Bus with 3.3V Auxiliary
Hot Swap Controller
The LTC
4241 is a Hot Swap controller that allows a board
to be safely inserted and removed from a live PCI-bus slot.
It has a primary controller that controls the four PCI
supplies and an independent auxiliary controller to control
the 3.3V auxiliary supply. External N-channel transistors
are used to control the 3.3V, 5V and 3.3V auxiliary supplies
while on-chip switches control the 12V and 12V supplies.
The 3.3V, 5V and 3.3V auxiliary supplies can be ramped up
at an adjustable rate. Electronic circuit breakers protect all
five supplies against overcurrent faults. The foldback
current limit feature reduces current spikes and power
dissipation when shorts occur. The PWRGD output of the
primary controller indicates when all four PCI supplies are
within tolerance. The FAULT output indicates an overcurrent
condition for any of the five supplies.
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.
s
PCI-Based Servers
s
Computer Systems
AUXIN AUXSENSE AUXGATE 3V
IN
3V
SENSE
GATE
3V
OUT
5V
IN
5V
SENSE
5V
OUT
GND
12V
IN
V
EEIN
AUXON
ON
FAULT
PWRGD
C3
10nF
R6
10
C1
0.047
F
C2
0.1
F
R5
10
R3
0.07
R2
0.005
R4
10
R7
100
R1
0.007
LOGIC
RESET
R8 10k
R9 10k
LTC4241
8
1
2
12
5
6
7
20
19
4
11
10
9
13
14
15
3
17
16
18
PCI
POWER
SYSTEM
CONTROLLER
SYSTEM
POWER
SUPPLY
BACKPLANE
CONNECTOR
GND
5V
5A
3.3V
7.6A
3.3V
AUX
500mA
12V
500mA
12V
100mA
Q1
IRF7413
Q2
IRF7413
Q3
Si2306DS
4241 F01
12V
OUT
V
EEOUT
TIMER
RESET
Figure 1. Hot Swappable PCI and 3.3V Auxiliary Supplies
LTC4241
2
sn4241 4241f
ORDER PART
NUMBER
T
JMAX
= 150
C,
JA
= 135
C/W
LTC4241CGN
LTC4241IGN
ABSOLUTE AXI U
RATI GS
W
W
W
U
PACKAGE/ORDER I FOR ATIO
U
U
W
(Note 1)
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
C. V
12VIN
= 12V, V
VEEIN
= 12V, V
3VIN
= 3.3V, V
5VIN
= 5V,
V
AUXIN
= 3.3V. (Note 2)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
I
DD
V
12VIN
Supply Current
ON = V
12VIN
q
2.5
8
mA
V
AUXIN
Supply Current
AUXON = V
AUXIN
q
0.5
1.5
mA
V
LKO
Undervoltage Lockout,
12V
IN
q
6.5
9
10.8
V
Low-to-High Transition
3V
IN
q
2.25
2.50
2.75
V
5V
IN
q
3.65
3.90
4.15
V
AUXIN
q
2.35
2.60
2.85
V
V
LKH
Undervoltage Lockout Hysteresis
3V
IN
, 5V
IN
20
mV
AUXIN
120
mV
V
SENSE5(TH)
Current Limit Sense Voltage
V
5VOUT
= 0V
q
5.5
9
14.5
mV
Threshold (V
5VIN
V
5VSENSE
)
V
5VOUT
> 4V
q
40
55
70
mV
V
SENSE3(TH)
Current Limit Sense Voltage
V
3VOUT
= 0V
q
5.5
9
14.5
mV
Threshold (V
3VIN
V
3VSENSE
)
V
3VOUT
> 2V
q
40
55
70
mV
t
CB
Circuit Breaker Trip Filter Time
(V
5VIN
V
5VSENSE
) = Step 0 to 100mV
17
s
(V
AUXIN
V
AUXSENSE
) = Step 0 to 100mV
8
s
I
GATE
GATE Pin Output Current
ON High, FAULT High, V
GATE
= GND
q
20
60
100
A
ON Low, FAULT High, V
GATE
= 5V
200
A
ON High, FAULT Low, V
GATE
= 5V
5
25
35
mA
Consult LTC Marketing for parts specified with wider operating temperature ranges.
GN PACKAGE
20-LEAD NARROW PLASTIC SSOP
1
2
3
4
5
6
7
8
9
10
TOP VIEW
20
19
18
17
16
15
14
13
12
11
12V
OUT
V
EEOUT
5V
OUT
5V
IN
5V
SENSE
GATE
3V
SENSE
3V
IN
AUXON
AUXIN
12V
IN
V
EEIN
3V
OUT
TIMER
ON
FAULT
PWRGD
GND
AUXGATE
AUXSENSE
Supply Voltages
12V
IN
................................................................... 14V
V
EEIN
.................................................................. 14V
AUXIN ................................................................... 7V
Input Voltage
ON ......................................................... 0.3V to 14V
AUXON .................................................. 0.3V to 14V
Output Voltages
(FAULT, PWRGD) .................................. 0.3V to 14V
Analog Voltages
TIMER, 3V
IN
, 3V
SENSE
, GATE,
5V
SENSE
, 5V
IN .............................
0.3V to (12V
IN
+ 0.3V)
3V
OUT
, 5V
OUT
........................................ 0.3V to 14V
AUXSENSE .......................... 0.3V to (AUXIN + 0.3V)
V
EEOUT
................................................ 14V to + 0.3V
12V
OUT
.................................................. 0.3V to 14V
AUXGATE ......................... Internally Limited (Note 3)
Operating Temperature Range
LTC4241CGN ........................................... 0
C to 70
C
LTC4241IGN ........................................40
C to 85
C
Storage Temperature Range ..................65
C to 150
C
Lead Temperature (Soldering,10sec).................... 300
C
DC ELECTRICAL CHARACTERISTICS
LTC4241
3
sn4241 4241f
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2 : All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
GATE
External Gate Voltage
(V
12VIN
V
GATE
)
q
100
200
mV
V
DROP
Internal Switch Voltage Drop
(V
12VIN
V
12VOUT
), I
12VOUT
= 500mA
q
200
600
mV
(V
EEOUT
V
VEEIN
), I
VEEIN
= 100mA
q
120
250
mV
I
CL(12)
Current Limit
12V
IN
= 12V, 12V
OUT
= 0V, TIMER = GND
q
50
300
575
mA
12V
IN
= 12V, 12V
OUT
= 11V, TIMER = GND
q
525
850
1500
mA
I
CL(VEE)
Current Limit
V
EEIN
= 12V, V
EEOUT
= 0V, TIMER = GND
q
50
200
425
mA
V
EEIN
= 12V, V
EEOUT
= 11V, TIMER = GND
q
250
450
750
mA
T
TS
Thermal Shutdown Temperature
150
C
V
PG(TH)
Power Good Threshold Voltage
V
12VOUT
Rising
q
10.8
11.1
11.4
V
V
VEEOUT
Falling
q
10.2
10.5
10.8
V
V
3VOUT
Rising
q
2.8
2.9
3.0
V
V
5VOUT
Rising
q
4.5
4.65
4.78
V
V
PGH
Power Good Hysteresis
3V
OUT
20
mV
5V
OUT
30
mV
12V
OUT
, V
EEOUT
50
mV
V
IL
Input Low Voltage
ON, AUXON
q
0.8
V
V
IH
Input High Voltage
ON, AUXON
q
2
V
V
OL
Output Low Voltage
FAULT, PWRGD , I
OL
= 3mA
q
0.4
V
I
IN
AUXON Pin Input Current
AUXON = GND
q
0.08
10
A
AUXON = V
AUXIN
q
0.08
10
A
ON Pin Input Current
ON = GND
q
0.08
10
A
ON = V
12VIN
q
0.08
10
A
5V
SENSE
Input Current
5V
SENSE
= 5V
q
50
100
A
3V
SENSE
Input Current
3V
SENSE
= 3V
q
50
100
A
5V
IN
Input Current
5V
IN
= 5V
q
580
900
A
3V
IN
Input Current
3V
IN
= 3V
q
310
550
A
5V
OUT
Input Current
5V
OUT
= 5V, ON = V
12VIN
q
260
500
A
3V
OUT
Input Current
3V
OUT
= 3V, ON = V
12VIN
q
150
350
A
R
DIS
5V
OUT
Discharge Impedance
ON = GND
60
3V
OUT
Discharge Impedance
ON = GND
50
12V
OUT
Discharge Impedance
ON = GND
450
V
EEOUT
Discharge Impedance
ON = GND
1600
I
TIMER
TIMER Pin Current
Timer On, V
TIMER
= GND,
q
15
22
27
A
Timer Off, V
TIMER
= 5V,
45
mA
V
TIMER
TIMER Threshold Voltage
(V
12VIN
V
TIMER
)
q
0.5
0.9
1.3
V
V
AUXCB
Circuit Breaker Trip Voltage
(V
AUXIN
V
AUXSENSE
)
q
40
50
60
mV
I
AUXGATE
AUXGATE Gate Output Current
AUXON High, FAULT High, V
AUXGATE
= GND
q
6
10
14
A
AUXON Low, FAULT High, V
AUXGATE
= 5V
200
A
AUXON High, FAULT Low, V
AUXGATE
= 10V
50
mA
V
AUXGATE
External AUXGATE Gate Voltage
(V
AUXGATE
V
AUXIN
), V
AUXIN
= 3.3V
q
5
8
11
V
Note 3 : An internal zener on the AUXGATE pin clamps the charge pump
voltage to a typical maximum operating voltage of 12V. External overdrive
of the AUXGATE pin beyond the internal zener voltage may damage the
device.
DC ELECTRICAL CHARACTERISTICS
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
C. V
12VIN
= 12V, V
VEEIN
= 12V, V
3VIN
= 3.3V, V
5VIN
= 5V,
V
AUXIN
= 3.3V. (Note 2)
LTC4241
4
sn4241 4241f
3.3V and 5V Current
Foldback Profile
12V Current Foldback Profile
12V Current Foldback Profile
5V
IN
Current Limit Voltage
vs Temperature
3V
IN
Current Limit Voltage
vs Temperature
12V
IN
Current Limit
vs Temperature
V
EEIN
Current Limit
vs Temperature
(V
AUXIN
V
AUXSENSE
)
Circuit Breaker Trip Voltage
vs Temperature
GATE, AUXGATE Output Source
Current vs Temperature
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
OUTPUT VOLTAGE (V)
0.5
OUTPUT CURRENT (A)
12
10
8
6
4
2
0
2.5
1.5
3.5
4.5
4241 G01
5.5
3V
OUT
5V
OUT
3V
IN
= 3.3V
5V
IN
= 5V
R
SENSE
= 0.005
OUTPUT VOLTAGE (V)
0
1
2
3
4
5
6
7
8
9 10 11 12
OUTPUT CURRENT (mA)
1100
1000
900
800
700
600
500
400
300
200
100
0
4241 G02
12V
IN
= 12V
OUTPUT VOLTAGE (V)
0 1 2 3 4 5 6 7 8 9 10 11 12
OUTPUT CURRENT (mA)
1100
1000
900
800
700
600
500
400
300
200
100
0
4241 G03
V
EEIN
= 12V
TEMPERATURE (
C)
75 50 25
CURRENT LIMIT VOLTAGE (mV)
25
50
0
70
60
50
40
30
20
10
0
4241 G05
125 150
75 100
3V
OUT
= 3.3V
3V
OUT
= 0V
TEMPERATURE (
C)
75 50 25
CURRENT LIMIT (mA)
25
50
0
1200
1000
800
600
400
200
0
4241 G06
125 150
75 100
12V
OUT
= 11V
12V
OUT
= 0V
TEMPERATURE (
C)
75 50 25
CURRENT LIMIT (mA)
25
50
0
600
500
400
300
200
100
0
4241 G07
125 150
75 100
V
EEOUT
= 11V
V
EEOUT
= 0V
TEMPERATURE (
C)
75 50 25
CIRCUIT BREAKER TRIP VOLTAGE (mV)
25
50
0
55
54
53
52
51
50
49
48
47
46
45
4241 G08
125 150
75 100
TEMPERATURE (
C)
75 50 25
GATE OUTPUT SOURCE CURRENT (
A)
AUXGATE OUTPUT SOURCE CURRENT (
A)
25
50
0
90
80
70
60
50
40
30
20
10
12.5
12.0
11.5
11.0
10.5
10.0
9.5
9.0
8.5
4241 G09
125 150
75 100
GATE
AUXGATE
TEMPERATURE (
C)
75 50 25
CURRENT LIMIT VOLTAGE (mV)
25
50
0
70
60
50
40
30
20
10
0
4241 G04
125 150
75 100
5V
OUT
= 5V
5V
OUT
= 0V
LTC4241
5
sn4241 4241f
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
GATE, AUXGATE Output Sink
Current vs Temperature
GATE, AUXGATE Fast Pull-Down
Current vs Temperature
(V
AUXGATE
V
AUXIN
)
vs Temperature
AUXGATE Voltage vs Temperature
12V Internal Switch Voltage Drop
vs Temperature
V
EE
Internal Switch Voltage Drop
vs Temperature
Power Good Threshold Voltage
vs Temperature (12V
OUT
)
Power Good Threshold Voltage
vs Temperature (3V
OUT
)
Power Good Threshold Voltage
vs Temperature (5V
OUT
)
TEMPERATURE (
C)
75 50 25
OUTPUT SINK CURRENT (
A)
25
50
0
350
300
250
200
150
100
50
4241 G10
125 150
75 100
GATE
AUXGATE
TEMPERATURE (
C)
75 50 25
FAST PULL-DOWN CURRENT (mA)
25
50
0
80
70
60
50
40
30
20
10
0
4241 G11
125 150
75 100
AUXGATE
GATE
TEMPERATURE (
C)
75 50 25
(V
AUXGATE
V
AUXIN
) (V)
25
50
0
8.20
8.15
8.10
8.05
8.00
7.95
7.90
7.85
7.80
7.75
4241 G12
125 150
75 100
AUXIN = 3.3V
TEMPERATURE (
C)
75 50 25
AUXGATE VOLTAGE (V)
25
50
0
11.75
11.60
11.45
11.30
11.15
11.00
10.85
10.70
4241 G13
125 150
75 100
TEMPERATURE (
C)
75 50 25
INTERNAL SWITCH VOLTAGE DROP (mV)
25
50
0
325
300
275
250
225
200
175
150
125
100
4241 G14
125 150
75 100
I
12VOUT
= 500mA
TEMPERATURE (
C)
75 50 25
INTERNAL SWITCH VOLTAGE DROP (mV)
25
50
0
200
180
160
140
120
100
80
60
40
4241 G15
125 150
75 100
I
VEEIN
= 100mA
TEMPERATURE (
C)
75 50 25
POWER GOOD THRESHOLD VOLTAGE (V)
25
50
0
11.20
11.15
11.10
11.05
11.00
10.95
10.90
4241 G16
125 150
75 100
TEMPERATURE (
C)
75 50 25
POWER GOOD THRESHOLD VOLTAGE (V)
25
50
0
4.68
4.67
4.66
4.65
4.64
4.63
4.62
4.61
4.60
4241 G17
125 150
75 100
TEMPERATURE (
C)
75 50 25
POWER GOOD THRESHOLD VOLTAGE (V)
25
50
0
2.915
2.910
2.905
2.900
2.895
2.890
2.885
2.880
2.875
4241 G18
125 150
75 100
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