LTC4244/LTC4244-1
Rugged, CompactPCI Bus
Hot Swap Controllers
FEATURES
s
s
DESCRIPTIO
s
s
s
s
s
s
Controls –12V, 3.3V, 5V and 12V Supplies
±14.4V
Absolute Maximum Rating for 12V
IN
and –12V
IN
Input Pins
Insensitive to Supply Voltage Transients
Adjustable Foldback Current Limit with Circuit Breaker
LOCAL_PCI_RST# Logic On-Chip
PRECHARGE Output Biases I/O Pins During Card
Insertion and Extraction
LTC4244-1 Designed for Applications without –12V
Available in 20-Lead Narrow SSOP Package
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 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#.
TYPICAL APPLICATIO
5V
LONG 5V
3.3V
LONG 3.3V
C8
0.01µF PER
POWER PIN
R22
2.7Ω
C9
0.01µF PER
POWER PIN
5V
IN
R2
Q2
0.007Ω IRF7457
3.3V
IN
R21
1.8Ω
C6
0.01µF
C7
0.01µF
Z3
Z4
R1
0.005Ω
Q1
IRF7457
R3
10Ω
Z1
12V
–12V
Z2
3.3V
IN
3.3V
SENSE
GATE 3.3V
OUT
5V
IN
12V
IN
V
EEIN
R19 1k
OFF/ON
R20
1.2k
R18 10k
FAULT
PWRGD
RESETIN
GND PRECHARGE
LTC4244
5V
SENSE
BD_SEL#
LONG V(I/O)
R17
10k
HEALTHY#
PCI_RST#
R15
1Ω
C4
0.01µF
GROUND
I/O DATA LINE 1
R13
10Ω
R16
1Ω
C5
0.01µF
TIMER
DRIVE RESETOUT
C3 4.7nF
R9 24Ω
R8 1k
LOCAL_PCI_RST#
R10 18Ω
R11
10k
R12
10k
I/O PIN 1
I/O PIN 128
1V
±10%
Q3
R7 12Ω
MMBT2222A
•
•
•
I/O DATA LINE 128
Z1, Z2: SMAJ12A
•
•
•
Z3, Z4: SMAJ5.0A
R14
10Ω
•
•
•
Figure 1. Typical Compact PCI Application
42441f
+
U
+
C
LOAD(5VOUT)
V
OUT
5V
5A
V
OUT
3.3V
7A
U
U
+
C
LOAD(3.3VOUT)
R4
10Ω
C1
R5 0.33µF
1k
5V
OUT
12V
OUT
+
C
LOAD(12VOUT)
V
OUT
12V
500mA
V
EEOUT
–12V
100mA
V
EEOUT
C
LOAD(VEEOUT)
C2
0.082µF
R6
10k
V
OUT
3.3V
V
IN
3.3V
RESET#
I/O #1
PCI
BRIDGE
I/O #128 CHIP
4244 F01
1
LTC4244/LTC4244-1
ABSOLUTE
(Notes 1, 2, 3)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
12V
IN
V
EEIN
5V
OUT
TIMER
OFF/ON
FAULT
PWRGD
GND
RESETIN
1
2
3
4
5
6
7
8
9
20 12V
OUT
19 V
EEOUT
18 3.3V
OUT
17 3.3V
IN
16 3.3V
SENSE
15 GATE
14 5V
SENSE
13 5V
IN
12 PRECHARGE
11 DRIVE
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
RESETOUT 10
GN PACKAGE
20-LEAD PLASTIC SSOP
T
JMAX
= 140°C,
θ
JA
= 135°C/ W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL
I
DD
V
LKO
PARAMETER
V
12VIN
Supply Current
Undervoltage Lockout
CONDITIONS
OFF/ON = 0V
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.
MIN
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
TYP
4
9
4.25
2.5
–9.25
9.25
16
51
16
51
52
52
25
25
–67
60
8
0.6
225
110
MAX
10
10
4.5
2.75
–10.25
10.25
21
56
21
56
57
57
35
35
–100
100
16
1
600
250
UNITS
mA
V
V
V
V
V
mV
mV
mV
mV
mV
mV
µs
µs
µA
µA
mA
V
mV
mV
12V
IN
, Ramping Down
5V
IN
, Ramping Down
3.3V
IN
, Ramping Down
V
EEIN
, Ramping Up (LTC4244 Only)
TIMER, Ramping Down, V
12VIN
= 6V
V
FB
= (V
5VIN
– V
5VSENSE
), V
5VOUT
= 0V, TIMER = 0V
V
FB
= (V
5VIN
– V
5VSENSE
), V
5VOUT
= 3V, TIMER = 0V
V
FB
= (V
3.3VIN
– V
3.3VSENSE
), V
3.3VOUT
= 0V, TIMER = 0V
V
FB
= (V
3.3VIN
– V
3.3VSENSE
), V
3.3VOUT
= 2V, TIMER = 0V
V
CB
= (V
5VIN
– V
5VSENSE
), TIMER = FLOAT
V
CB
= (V
3.3VIN
– V
3.3VSENSE
), TIMER = FLOAT
8
4
2.25
–8.25
8.25
11
46
11
46
45
45
17
17
–20
20
4
V
FB
Foldback Current Limit Voltage
V
CB
t
OC
I
GATE(UP)
I
GATE(DN)
I
GATE(FAULT)
∆V
GATE
∆V
12V
∆V
VEE
Circuit Breaker Trip Voltage
Overcurrent Fault Response Time (V
5VIN
– V
5VSENSE
) = 100mV, TIMER = FLOAT
(V
3.3VIN
– V
3.3VSENSE
) = 100mV, TIMER = FLOAT
GATE Pin Output Current
OFF/ON = 0V, V
GATE
= 2V, TIMER = 0V
V
GATE
= 5V, OFF/ON = 4V
OFF/ON = 0V, V
GATE
= 2V, TIMER = FLOAT, FAULT = 0V
External Gate Voltage
Internal Switch Voltage Drop
∆V
GATE
= (V
12VIN
– V
GATE
), I
GATE
= –1µA
∆V
12V
= (V
12VIN
– V
12VOUT
), I = 500mA
∆V
VEE
= (V
EEOUT
– V
EEIN
), I
EE
= 100mA
2
U
42441f
W
U
U
W W
W
LTC4244/LTC4244-1
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
I
CL
Current Foldback
CONDITIONS
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.
MIN
q
q
q
q
TYP
–360
–850
225
610
150
11.1
4.61
2.90
–11.1
MAX
–1000
–1500
350
870
11.4
4.75
3.00
–11.4
0.8
UNITS
mA
mA
mA
mA
°C
V
V
V
V
V
V
µA
µA
µA
µA
µA
µA
mA
µA
µA
µA
µA
µA
µA
mA
V
V
V
Ω
Ω
Ω
Ω
V
V
12V
IN
= 12V, 12V
OUT
= 0V, TIMER = 0V
12V
IN
= 12V, 12V
OUT
= 10V, TIMER = 0V
V
EEIN
= –12V, V
EEOUT
= 0V, TIMER = 0V
V
EEIN
= –12V, V
EEOUT
= –10V, TIMER = 0V
Junction Temperature, Ramping Up
12V
OUT
, Ramping Down
5V
OUT
, Ramping Down
3.3V
OUT
, Ramping Down
V
EEOUT
, Ramping Up, LTC4244 Only
OFF/ON, RESETIN, FAULT
OFF/ON, RESETIN, FAULT
OFF/ON, RESETIN = 0V
OFF/ON, RESETIN = 12V
RESETOUT, FAULT = 5V, OFF/ON = 0V, RESETIN = 3.3V
PWRGD = 5V, OFF/ON = 4V
5V
SENSE
= 5V, 5V
OUT
= 0V
3.3V
SENSE
= 3.3V, 3.3V
OUT
= 0V
5V
IN
= 5V, TIMER = 0V
3.3V
IN
= 3.3V, TIMER = FLOAT
3.3V
IN
= 3.3V, TIMER = 0V
5V
OUT
= 5V, OFF/ON = 0V, TIMER = 0V
3.3V
OUT
= 3.3V, OFF/ON = 0V, TIMER = 0V
V
PRECHARGE
= 1V
OFF/ON = 0V, V
TIMER
= 0V
OFF/ON = 5V, V
TIMER
= 5V
TIMER_HI, (V
12VIN
– V
TIMER
), FAULT = 0V, Ramping Up
TIMER_LO, V
TIMER
, Ramping Down
∆V
TIMER
= (V
12VIN
– V
TIMER
), I
TIMER
= –1µA
OFF/ON = 4V
OFF/ON = 4V
OFF/ON = 4V
OFF/ON = 4V
PWRGD, RESETOUT, FAULT, I = 1mA
V
DRIVE
= 2V
–100
–550
50
350
10.8
4.50
2.80
–10.8
2
T
TS
V
TH
Thermal Shutdown Temperature
Power Good Threshold Voltage
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
V
IL
V
IH
I
IN
Logic Input Low Voltage
Logic Input High Voltage
OFF/ON, RESETIN Input Current
RESETOUT, FAULT Leakage
Current
PWRGD Output Current
5V
SENSE
Input Current
3.3V
SENSE
Input Current
5V
IN
Input Current
3.3V
IN
Input Current
5V
OUT
Input Current
3.3V
OUT
Input Current
PRECHARGE Input Current
±10
±10
±10
±10
57
56
0.8
510
400
107
170
0.1
16
25
1.3
0.5
21
45
1.6
0.8
440
200
200
390
0.95
1
100
100
1.5
700
550
200
300
10
26
70
1.9
1.1
1
1000
500
500
1000
0.4
1.05
I
TIMER
V
TIMER
∆V
TIMER
R
DIS
TIMER Pin Current
TIMER Threshold Voltage
External Timer Voltage
12V
OUT
Discharge Resistance
5V
OUT
Discharge Resistance
3.3V
OUT
Discharge Resistance
V
EEOUT
Discharge Resistance
Output Low Voltage
PRECHARGE Reference Voltage
V
OL
V
PXG
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.
42441f
3
LTC4244/LTC4244-1
TYPICAL PERFOR A CE CHARACTERISTICS
3.3V and 5V Current Foldback
Profile
60
50
3.3V
VOLTAGE (mV)
5V
CURRENT (A)
0.6
0.5
0.4
0.3
0.2
0.1
30
20
10
0
0
1
2
3
VOLTAGE (V)
4
5
4244 G01
CURRENT (A)
40
12V Foldback Current Limit vs
Temperature
0.9
0.8
0.7
CURRENT (A)
12V
OUT
= 10V
0.5
0.6
0.5
0.4
0.3
0.2
0.1
0.1
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G04
CURRENT (A)
12V
OUT
= 0V
0.3
0.2
V
EEOUT
= 0V
VOLTAGE (V)
V
EE
Internal Switch Voltage Drop
vs Temperature
0.14
0.12
0.10
I
VEEIN
= 100mA
60
VOLTAGE (mV)
0.08
0.06
0.04
0.02
0
–50
30
20
10
0
–50
5V
OUT
= 0V
VOLTAGE (mV)
VOLTAGE (V)
–25
0
25
50
TEMPERATURE (°C)
4
U W
75
4244 G07
12V
OUT
Current vs 12V
OUT
Voltage
1.0
0.9
0.8
0.7
–0.5
–0.4
–0.3
–0.2
–0.1
0
0
2
4
6
8
VOLTAGE (V)
10
12
4244 G02
V
EEOUT
Current vs V
EEOUT
Voltage
–0.6
0
0
–2
–4
–6
–8
VOLTAGE (V)
–10
–12
4244 G03
V
EE
Foldback Current Limit vs
Temperature
0.6
V
EEOUT
= 10V
0.25
0.20
0.15
0.10
0.05
0.30
12V Internal Switch Voltage Drop
vs Temperature
I
12VOUT
= 550mA
0.4
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G05
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G06
5V
IN
Foldback Current Limit
Voltage vs Temperature
60
5V
OUT
= 3V
50
40
50
40
30
20
10
3.3V
IN
Foldback Current Limit
Voltage vs Temperature
3.3V
OUT
= 2V
3.3V
OUT
= 0V
100
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G08
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G09
42441f
LTC4244/LTC4244-1
TYPICAL PERFOR A CE CHARACTERISTICS
3.3V
IN
and 5V
IN
Circuit Breaker
Trip Voltage vs Temperature
52.0
51.8
51.6
51.4
5V
IN
25.0
24.5
24.0
23.5
23.0
22.5
22.0
21.5
–50
TIME (µs)
51.2
51.0
50.8
50.6
50.4
50.2
50.0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G10
CURRENT (mA)
VOLTAGE (mV)
3.3V
IN
12V
IN
Undervoltage Lockout vs
Temperature
9.30
9.25
9.20
RAMPING-UP
–9.22
–9.24
VOLTAGE (V)
VOLTAGE (V)
9.15
9.10
9.05
9.00
8.95
–50
RAMPING-DOWN
–9.28
–9.30
–9.32
–9.34
–9.36
–50
RAMPING-DOWN
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G14
VOLTAGE (V)
–25
0
25
50
TEMPERATURE (°C)
3.3V
IN
Undervoltage Lockout vs
Temperature
2.54
RAMPING-UP
2.53
2.52
11.085
11.080
11.090
VOLTAGE (V)
VOLTAGE (V)
2.50
2.49
2.48
2.47
2.46
2.45
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G16
11.075
11.070
11.065
11.060
11.055
–50
VOLTAGE (V)
2.51
RAMPING-DOWN
U W
75
4244 G13
3.3V
IN
and 5V
IN
Circuit Breaker
Trip Filter Time vs Temperature
3.94
3.93
3.92
3.91
3.90
3.89
3.88
12V
IN
Supply Current vs
Temperature
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G11
3.87
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G12
V
EEIN
Undervoltage Lockout vs
Temperature
4.34
4.32
RAMPING-UP
–9.26
4.30
4.28
4.26
4.24
4.22
5V
IN
Undervoltage Lockout vs
Temperature
RAMPING-UP
RAMPING-DOWN
100
4.20
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G15
12V
OUT
Powergood Threshold
Voltage vs Temperature
–11.050
–11.055
–11.060
–11.065
–11.070
–11.075
V
EEIN
Powergood Threshold
Voltage vs Temperature
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G17
–11.080
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4244 G18
42441f
5
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