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1
LTC4244/LTC4244-1
42441f
APPLICATIO S
U
FEATURES
TYPICAL APPLICATIO
U
DESCRIPTIO
U
s
Controls 12V, 3.3V, 5V and 12V Supplies
s
14.4V Absolute Maximum Rating for 12V
IN
and 12V
IN
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 12V
s
Available in 20-Lead Narrow SSOP Package
, LTC and LT are registered trademarks of Linear Technology Corporation.
s
Hot Board Insertion into CompactPCI Bus
The LTC
4244/LTC4244-1 are Hot Swap
TM
controllers that
allow a board to be safely inserted into and removed from
a CompactPCI
TM
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 V
CC
allowing the LTC4244/
LTC4244-1 to function without interruption in the pres-
ence of voltage spikes on the 12V
IN
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#.
3.3V
IN
12V
IN
12V
OUT
V
EEIN
OFF/ON
Z4
5V
IN
R4
10
C
LOAD(5VOUT)
V
OUT
5V
5A
V
OUT
3.3V
7A
R5
1k
C1
0.33
F
R3
10
R1
0.005
R2
0.007
Q1
IRF7457
Q2
IRF7457
3.3V
OUT
3.3V
SENSE
GND PRECHARGE
5V
IN
5V
SENSE
DRIVE
R9 24
1V
10%
Q3
MMBT2222A
C3 4.7nF
V
IN
3.3V
4244 F01
LTC4244
GATE
5V
OUT
+
C
LOAD(3.3VOUT)
+
V
OUT
12V
500mA
C
LOAD(12VOUT)
+
V
EEOUT
TIMER
RESETOUT
I/O #1
I/O #128
V
EEOUT
12V
100mA
V
OUT
3.3V
C
LOAD(VEEOUT)
C2
0.082
F
+
Z3
Z2
Z1
R17
10k
3.3V
IN
R22
2.7
C9
0.01
F PER
POWER PIN
C7
0.01
F
C8
0.01
F PER
POWER PIN
R21
1.8
R19 1k
FAULT
PWRGD
RESETIN
R18 10k
R20
1.2k
R16
1
C6
0.01
F
R8 1k
R7 12
R6
10k
R10 18
R11
10k
R13
10
R14
10
R12
10k
C5
0.01
F
R15
1
C4
0.01
F
I/O DATA LINE 1
I/O DATA LINE 128
Z1, Z2: SMAJ12A
Z3, Z4: SMAJ5.0A
I/O PIN 128
RESET#
PCI
BRIDGE
CHIP
I/O PIN 1
GROUND
PCI_RST#
LOCAL_PCI_RST#
HEALTHY#
LONG V(I/O)
BD_SEL#
12V
12V
LONG 3.3V
LONG 5V
3.3V
5V
Figure 1. Typical Compact PCI Application
Hot Swap is a trademark of Linear Technology Corporation.
CompactPCI is a trademark of the PCI Industrial Computer Manufacturers Group.
Rugged, CompactPCI Bus
Hot Swap Controllers
2
LTC4244/LTC4244-1
42441f
GN PACKAGE
20-LEAD 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
IN
V
EEIN
5V
OUT
TIMER
OFF/ON
FAULT
PWRGD
GND
RESETIN
RESETOUT
12V
OUT
V
EEOUT
3.3V
OUT
3.3V
IN
3.3V
SENSE
GATE
5V
SENSE
5V
IN
PRECHARGE
DRIVE
(Notes 1, 2, 3)
Supply Voltages
12V
IN
................................................................ 14.4V
V
EEIN
.............................................................. 14.4V
Input Voltages (OFF/ON, RESETIN) ........ 0.3V to 13.5V
Output Voltages (FAULT, PWRGD, RESETOUT)
........................................................... 0.3V to 13.5V
Analog Voltages and Currents
5V
OUT
, DRIVE, 5V
IN
, 3.3V
SENSE
, 3.3V
IN
, 3.3V
OUT
, 5V
SENSE
........................................................... 0.3V to 13.5V
PRECHARGE, GATE .......................................
20mA
V
EEOUT
................................................ 14.4V to 0.3V
TIMER, 12V
OUT ...........................................
0.3V to 14.4V
Operation Temperature Range
LTC4244C/LTC4244C-1 ........................... 0
C to 70
C
LTC4244I/LTC4244I-1 ........................ 40
C to 85
C
Storage Temperature Range ................. 65
C to 150
C
Lead Temperature (Soldering, 10 sec).................. 300
C
ORDER PART
NUMBER
LTC4244CGN
LTC4244CGN-1
LTC4244IGN
LTC4244IGN-1
T
JMAX
= 140
C,
JA
= 135
C/ W
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
I
DD
V
12VIN
Supply Current
OFF/ON = 0V
q
4
10
mA
V
LKO
Undervoltage Lockout
12V
IN
, Ramping Down
q
8
9
10
V
5V
IN
, Ramping Down
q
4
4.25
4.5
V
3.3V
IN
, Ramping Down
q
2.25
2.5
2.75
V
V
EEIN
, Ramping Up (LTC4244 Only)
q
8.25
9.25
10.25
V
TIMER, Ramping Down, V
12VIN
= 6V
q
8.25
9.25
10.25
V
V
FB
Foldback Current Limit Voltage
V
FB
= (V
5VIN
V
5VSENSE
), V
5VOUT
= 0V, TIMER = 0V
q
11
16
21
mV
V
FB
= (V
5VIN
V
5VSENSE
), V
5VOUT
= 3V, TIMER = 0V
q
46
51
56
mV
V
FB
= (V
3.3VIN
V
3.3VSENSE
), V
3.3VOUT
= 0V, TIMER = 0V
q
11
16
21
mV
V
FB
= (V
3.3VIN
V
3.3VSENSE
), V
3.3VOUT
= 2V, TIMER = 0V
q
46
51
56
mV
V
CB
Circuit Breaker Trip Voltage
V
CB
= (V
5VIN
V
5VSENSE
), TIMER = FLOAT
q
45
52
57
mV
V
CB
= (V
3.3VIN
V
3.3VSENSE
), TIMER = FLOAT
q
45
52
57
mV
t
OC
Overcurrent Fault Response Time (V
5VIN
V
5VSENSE
) = 100mV, TIMER = FLOAT
q
17
25
35
s
(V
3.3VIN
V
3.3VSENSE
) = 100mV, TIMER = FLOAT
q
17
25
35
s
I
GATE(UP)
GATE Pin Output Current
OFF/ON = 0V, V
GATE
= 2V, TIMER = 0V
q
20
67
100
A
I
GATE(DN)
V
GATE
= 5V, OFF/ON = 4V
q
20
60
100
A
I
GATE(FAULT)
OFF/ON = 0V, V
GATE
= 2V, TIMER = FLOAT, FAULT = 0V
q
4
8
16
mA
V
GATE
External Gate Voltage
V
GATE
= (V
12VIN
V
GATE
), I
GATE
= 1
A
q
0.6
1
V
V
12V
Internal Switch Voltage Drop
V
12V
= (V
12VIN
V
12VOUT
), I = 500mA
q
225
600
mV
V
VEE
V
VEE
= (V
EEOUT
V
EEIN
), I
EE
= 100mA
q
110
250
mV
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ABSOLUTE AXI U RATI GS
W
W
W
U
PACKAGE/ORDER I FOR ATIO
U
U
W
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
EEIN
= 12V, V
3.3VIN
= 3.3V, V
5VIN
= 5V, unless
otherwise noted.
3
LTC4244/LTC4244-1
42441f
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
I
CL
Current Foldback
12V
IN
= 12V, 12V
OUT
= 0V, TIMER = 0V
q
100
360
1000
mA
12V
IN
= 12V, 12V
OUT
= 10V, TIMER = 0V
q
550
850
1500
mA
V
EEIN
= 12V, V
EEOUT
= 0V, TIMER = 0V
q
50
225
350
mA
V
EEIN
= 12V, V
EEOUT
= 10V, TIMER = 0V
q
350
610
870
mA
T
TS
Thermal Shutdown Temperature
Junction Temperature, Ramping Up
150
C
V
TH
Power Good Threshold Voltage
12V
OUT
, Ramping Down
q
10.8
11.1
11.4
V
5V
OUT
, Ramping Down
q
4.50
4.61
4.75
V
3.3V
OUT
, Ramping Down
q
2.80
2.90
3.00
V
V
EEOUT
, Ramping Up, LTC4244 Only
q
10.8
11.1
11.4
V
V
IL
Logic Input Low Voltage
OFF/ON, RESETIN, FAULT
q
0.8
V
V
IH
Logic Input High Voltage
OFF/ON, RESETIN, FAULT
q
2
V
I
IN
OFF/ON, RESETIN Input Current
OFF/ON, RESETIN = 0V
q
10
A
OFF/ON, RESETIN = 12V
q
10
A
RESETOUT, FAULT Leakage
RESETOUT, FAULT = 5V, OFF/ON = 0V, RESETIN = 3.3V
q
10
A
Current
PWRGD Output Current
PWRGD = 5V, OFF/ON = 4V
q
10
A
5V
SENSE
Input Current
5V
SENSE
= 5V, 5V
OUT
= 0V
q
57
100
A
3.3V
SENSE
Input Current
3.3V
SENSE
= 3.3V, 3.3V
OUT
= 0V
q
56
100
A
5V
IN
Input Current
5V
IN
= 5V, TIMER = 0V
q
0.8
1.5
mA
3.3V
IN
Input Current
3.3V
IN
= 3.3V, TIMER = FLOAT
q
510
700
A
3.3V
IN
= 3.3V, TIMER = 0V
q
400
550
A
5V
OUT
Input Current
5V
OUT
= 5V, OFF/ON = 0V, TIMER = 0V
q
107
200
A
3.3V
OUT
Input Current
3.3V
OUT
= 3.3V, OFF/ON = 0V, TIMER = 0V
q
170
300
A
PRECHARGE Input Current
V
PRECHARGE
= 1V
q
0.1
10
A
I
TIMER
TIMER Pin Current
OFF/ON = 0V, V
TIMER
= 0V
q
16
21
26
A
OFF/ON = 5V, V
TIMER
= 5V
q
25
45
70
mA
V
TIMER
TIMER Threshold Voltage
TIMER_HI, (V
12VIN
V
TIMER
), FAULT = 0V, Ramping Up
q
1.3
1.6
1.9
V
TIMER_LO, V
TIMER
, Ramping Down
q
0.5
0.8
1.1
V
V
TIMER
External Timer Voltage
V
TIMER
= (V
12VIN
V
TIMER
), I
TIMER
= 1
A
q
1
V
R
DIS
12V
OUT
Discharge Resistance
OFF/ON = 4V
q
440
1000
5V
OUT
Discharge Resistance
OFF/ON = 4V
q
200
500
3.3V
OUT
Discharge Resistance
OFF/ON = 4V
q
200
500
V
EEOUT
Discharge Resistance
OFF/ON = 4V
q
390
1000
V
OL
Output Low Voltage
PWRGD, RESETOUT, FAULT, I = 1mA
q
0.4
V
V
PXG
PRECHARGE Reference Voltage
V
DRIVE
= 2V
q
0.95
1
1.05
V
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
EEIN
= 12V, V
3.3VIN
= 3.3V, V
5VIN
= 5V, unless
otherwise noted.
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.
Note 3: The 12V
IN
and V
EEIN
pins will withstand transient surges up to
15V, respectively, upon hot insertion.
4
LTC4244/LTC4244-1
42441f
3.3V and 5V Current Foldback
Profile
12V
OUT
Current vs 12V
OUT
Voltage
V
EEOUT
Current vs V
EEOUT
Voltage
12V Foldback Current Limit vs
Temperature
V
EE
Foldback Current Limit vs
Temperature
12V Internal Switch Voltage Drop
vs Temperature
V
EE
Internal Switch Voltage Drop
vs Temperature
5V
IN
Foldback Current Limit
Voltage vs Temperature
3.3V
IN
Foldback Current Limit
Voltage vs Temperature
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
VOLTAGE (V)
0
VOLTAGE (mV)
1
3.3V
5V
2
3
4
4244 G01
5
60
50
40
30
20
10
0
VOLTAGE (V)
0
CURRENT (A)
2
4
6
10
8
4244 G02
12
1.0
0.9
0.7
0.5
0.3
0.8
0.6
0.4
0.2
0.1
0
VOLTAGE (V)
0
CURRENT (A)
2
4
6
10
8
4244 G03
12
0.6
0.5
0.3
0.4
0.2
0.1
0
TEMPERATURE (
C)
50
CURRENT (A)
25
0
25
75
50
4244 G04
100
0.9
0.8
0.7
0.6
0.5
0.3
0.4
0.2
0.1
0
12V
OUT
= 10V
12V
OUT
= 0V
TEMPERATURE (
C)
50
CURRENT (A)
25
0
25
75
50
4244 G05
100
0.6
0.5
0.3
0.4
0.2
0.1
0
V
EEOUT
= 10V
V
EEOUT
= 0V
TEMPERATURE (
C)
50
VOLTAGE (V)
25
0
25
75
50
4244 G06
100
0.30
0.25
0.15
0.20
0.10
0.05
0
I
12VOUT
= 550mA
TEMPERATURE (
C)
50
VOLTAGE (V)
25
0
25
75
50
4244 G07
100
0.14
0.12
0.10
0.06
0.08
0.04
0.02
0
I
VEEIN
= 100mA
TEMPERATURE (
C)
50
VOLTAGE (mV)
25
0
25
75
50
4244 G09
100
60
50
30
40
20
10
0
3.3V
OUT
= 2V
3.3V
OUT
= 0V
TEMPERATURE (
C)
50
VOLTAGE (mV)
25
0
25
75
50
4244 G08
100
60
50
30
40
20
10
0
5V
OUT
= 3V
5V
OUT
= 0V
5
LTC4244/LTC4244-1
42441f
3.3V
IN
and 5V
IN
Circuit Breaker
Trip Voltage vs Temperature
3.3V
IN
and 5V
IN
Circuit Breaker
Trip Filter Time vs Temperature
12V
IN
Supply Current vs
Temperature
12V
IN
Undervoltage Lockout vs
Temperature
V
EEIN
Undervoltage Lockout vs
Temperature
5V
IN
Undervoltage Lockout vs
Temperature
3.3V
IN
Undervoltage Lockout vs
Temperature
12V
OUT
Powergood Threshold
Voltage vs Temperature
V
EEIN
Powergood Threshold
Voltage vs Temperature
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
TEMPERATURE (
C)
50
VOLTAGE (mV)
25
0
25
75
50
4244 G10
100
52.0
51.6
51.8
51.4
51.2
51.0
50.6
50.8
50.4
50.2
50.0
5V
IN
3.3V
IN
TEMPERATURE (
C)
50
TIME (
s)
25
0
25
75
50
4244 G11
100
25.0
24.5
24.0
23.0
23.5
22.5
22.0
21.5
TEMPERATURE (
C)
50
CURRENT (mA)
25
0
25
75
50
4244 G12
100
3.94
3.93
3.92
3.90
3.91
3.89
3.88
3.87
TEMPERATURE (
C)
50
VOLTAGE (V)
25
0
25
75
50
4244 G13
100
9.30
9.25
9.20
9.10
9.15
9.05
9.00
8.95
RAMPING-UP
RAMPING-DOWN
TEMPERATURE (
C)
50
VOLTAGE (V)
25
0
25
75
50
4244 G14
100
9.22
9.24
9.26
9.30
9.28
9.32
9.34
9.36
RAMPING-UP
RAMPING-DOWN
TEMPERATURE (
C)
50
VOLTAGE (V)
25
0
25
75
50
4244 G15
100
4.34
4.32
4.30
4.26
4.28
4.24
4.22
4.20
RAMPING-UP
RAMPING-DOWN
TEMPERATURE (
C)
50
VOLTAGE (V)
25
0
25
75
50
4244 G16
100
2.54
2.53
2.52
2.50
2.51
2.49
2.48
2.45
2.46
2.47
RAMPING-UP
RAMPING-DOWN
TEMPERATURE (
C)
50
VOLTAGE (V)
25
0
25
75
50
4244 G17
100
11.090
11.085
11.080
11.070
11.075
11.065
11.060
11.055
TEMPERATURE (
C)
50
VOLTAGE (V)
25
0
25
75
50
4244 G18
100
11.050
11.055
11.060
11.070
11.065
11.075
11.080
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