FEATURES
s
s
s
LTC1644
CompactPCI Bus
Hot Swap Controller
DESCRIPTIO
The LTC
®
1644 is a Hot Swap
TM
controller that allows a board
to be safely inserted and removed from a CompactPCI bus
slot. External N-channel transistors control the 3.3V/5V
supplies, while on-chip switches control the
–12V and 12V supplies. The 3.3V and 5V supplies can be
ramped up at a programmable rate. Electronic circuit break-
ers protect all four supplies against overcurrent faults. The
PWRGD output indicates when all of the supply voltages are
within tolerance. The OFF/ON pin is used to cycle the board
power or reset the circuit breaker. The PRECHARGE output
can be used to bias the bus I/O pins during card insertion
and extraction. PCI_RST# is combined on-chip with
HEALTHY# in order to generate LOCAL_PCI_RST#.
, 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.
s
s
s
s
Allows Safe Board Insertion and Removal from a
Live, CompactPCI
TM
Bus
Controls –12V, 3.3V, 5V and 12V Supplies
Adjustable Foldback Current Limit with Circuit
Breaker
Dual-Level Circuit Breakers Protect 5V and 3.3V
Supplies from Overcurrent and Short-Circuit Faults
LOCAL_PCI_RST# Logic On-Chip
PRECHARGE Output Biases I/O Pins During Card
Insertion and Extraction
Adjustable Supply Voltage Power-Up Rate
APPLICATIO S
s
Hot Board Insertion into CompactPCI Bus
TYPICAL APPLICATIO
BACKPLANE
CONNECTOR
5V
LONG 5V
3.3V
PCB EDGE
BACKPLANE
CONNECTOR
C8
0.1µF
PER 10
POWER
PINS
C9
0.1µF
PER 10
POWER
PINS
R22 2.74Ω
3V
IN
*
R21 1.74Ω
Z3
5V
IN
*
R1
0.005Ω
Q1
IRF7413
R2
0.007Ω
LONG 3.3V
C6
0.01µF
C7
0.01µF
Z4
R3
10Ω
17
3V
IN
16
15
18
3V
OUT
13
5V
IN
3V
SENSE
GATE
5V
SENSE
Z1
12V
–12V
Z2
1
2
5V
IN
R20 1.2k
R19
1k
5
6
R18
2k
7
9
12V
IN
V
EEIN
OFF/ON
FAULT
PWRGD
RESETIN
GND
PRECHARGE
12
R10
18Ω 5%
R11
51k
C3 4.7nF
R12
51k
R9
24Ω
1V
±10%
Q3
MMBT2222A
DRIVE
11
LTC1644
20-PIN SSOP
BD_SEL#
EARLY V(I/O)
R17
2k
HEALTHY#
PCI_RST#
R15
1Ω
C4
0.01µF
GROUND
I/O DATA LINE 1
R16
1Ω
C5
0.01µF
TIMER
4
C2
0.1µF
R6
2k
3V
OUT
RESETOUT
10
8
R8 1k
3V
IN
R7
12Ω
I/O #1
I/O #128
1644 F01
R13 10Ω
RESET#
PCI
BRIDGE
CHIP
I/O PIN 1
I/O PIN 128
I/O DATA LINE 128
Z1, Z2: SMAJ12CA
R14 10Ω
*5V
IN
AND 3V
IN
MAY BE USED AS SOURCES OF EARLY POWER
Z3, Z4: 1PMT5.0AT3
Figure 1
1644f
+
U
U
U
Q2
IRF7413
+
C
LOAD(5VOUT)
5V
OUT
5V AT 5.7A
3V
OUT
3.3V AT 8A
+
R4
10Ω
14
3
5V
OUT
12V
OUT
20
R5
1k
C
LOAD(3VOUT)
C1
0.047µF
+
C
LOAD(12VOUT)
19
C
LOAD(VEEOUT)
12V
OUT
12V AT 500mA
V
EEOUT
V
EEOUT
–12V AT 100mA
• • •
• • •
• • •
1
LTC1644
ABSOLUTE
(Note 1)
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 3V
OUT
17 3V
IN
16 3V
SENSE
15 GATE
14 5V
SENSE
13 5V
IN
12 PRECHARGE
11 DRIVE
Supply Voltages
12V
IN
................................................................ 13.2V
V
EEIN
.................................................................. –14V
Input Voltages (Pins 5, 9) .......................– 0.3V to 13.5V
Output Voltages (Pins 6, 7, 10) ..............– 0.3V to 13.5V
Analog Voltages and Currents
Pins 3, 11 to 14, 16 to 18 ...................– 0.3V to 13.5V
Pins 4, 15 ............................. – 0.3V to (12V
IN
+ 0.3V)
V
EEOUT
...................................................– 14V to 0.3V
12V
OUT
...............................................– 0.3V to 13.2V
Operating Temperature Range
LTC1644C ............................................... 0°C to 70°C
LTC1644I ............................................ – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
LTC1644CGN
LTC1644IGN
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
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
3VIN
= 3.3V, V
5VIN
= 5V unless otherwise noted.
SYMBOL
I
DD
V
LKO
V
FB
PARAMETER
V
12VIN
Supply Current
Undervoltage Lockout
Foldback Current Limit Voltage
CONDITIONS
OFF/ON = 0V
12V
IN
, Ramping Down
3V
IN
, 5V
IN
, Ramping Down
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
3VIN
– V
3VSENSE
), V
3VOUT
= 0V, TIMER = 0V
V
FB
= (V
3VIN
– V
3VSENSE
), V
3VOUT
= 2V, TIMER = 0V
V
CB
= (V
5VIN
– V
5VSENSE
), TIMER = FLOAT
V
CB
= (V
3VIN
– V
3VSENSE
), TIMER = FLOAT
(V
5VIN
– V
5VSENSE
) = 100mV, TIMER = FLOAT
(V
3VIN
– V
3VSENSE
) = 100mV, TIMER = FLOAT
(V
5VIN
– V
5VSENSE
) = 200mV, TIMER = FLOAT
(V
3VIN
– V
3VSENSE
) = 200mV, TIMER = FLOAT
OFF/ON = 0V, V
GATE
= 0V, TIMER = 0V
V
GATE
= 5V, OFF/ON = 4V
OFF/ON = 0V, V
GATE
= 2V, TIMER = FLOAT, FAULT = 0V
∆V
GATE
= (V
12VIN
– V
GATE
), I
GATE
= –1µA
V
DROP
= (V
12VIN
– V
12VOUT
), I = 500mA
V
DROP
= (V
EEOUT
– V
EEIN
), I
EE
= 100mA
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
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
MIN
6.00
2.25
8
40
8
40
40
40
30
30
TYP
3
8.30
2.48
12
51
12
51
55
55
45
45
0.1
0.1
MAX
8
10.80
2.75
15
70
15
70
70
70
60
60
1.0
1.0
–100
300
20
200
600
250
– 600
– 1500
300
650
UNITS
mA
V
V
mV
mV
mV
mV
mV
mV
µs
µs
µs
µs
µA
µA
mA
mV
mV
mV
mA
mA
mA
mA
°C
1644f
V
CB
t
OC
t
SC
I
CP
Circuit Breaker Trip Voltage
Overcurrent Fault Response Time
Short-Circuit Response Time
GATE Pin Output Current
– 20
100
3
– 65
225
10
50
200
110
∆V
GATE
V
DROP
I
CL
External Gate Voltage
Internal Switch Voltage Drop
Current Foldback
– 50
– 525
20
200
–360
– 840
100
320
130
T
TS
Thermal Shutdown Temperature
2
U
W
U
U
W W
W
LTC1644
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
3VIN
= 3.3V, V
5VIN
= 5V unless otherwise noted.
SYMBOL
V
TH
PARAMETER
Power Good Threshold Voltage
CONDITIONS
12V
OUT
V
EEOUT
3V
OUT
5V
OUT
V
3VONLY
=
V
5VIN
– V
3VIN
, V
5VOUT
= V
3VOUT
= 3V
V
EEIN
OFF/ON, RESETIN, FAULT
OFF/ON, RESETIN, FAULT
OFF/ON, RESETIN = 0V
OFF/ON, RESETIN = 12V
IN
RESETOUT, FAULT = 5V, OFF/ON = 0V, RESETIN = 3.3V
PWRGD = 5V, OFF/ON = 4V
5V
SENSE
= 5V, 5V
OUT
= 0V
3V
SENSE
= 3.3V, 3V
OUT
= 0V
5V
IN
= 5V, TIMER = 0V
3V
IN
= 3.3V, TIMER = FLOAT
3V
IN
= 3.3V, TIMER = 0V
5V
OUT
= 5V, OFF/ON = 0V, TIMER = 0V
3V
OUT
= 3.3V, OFF/ON = 0V, TIMER = 0V
OFF/ON = 0V, V
TIMER
= 0V
V
TIMER
= 5V, OFF/ON = 4V
(V
12VIN
– V
TIMER
), FAULT = 0V
OFF/ON = 4V
OFF/ON = 4V
OFF/ON = 4V
OFF/ON = 4V
PWRGD, RESETOUT, FAULT, I = 3mA
V
5VIN
= 5V
V
5VIN
= V
3VIN
= 3.3V
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
MIN
10.8
– 10.4
2.8
4.50
50
–4
2
TYP
11.1
– 10.5
2.9
4.62
107
– 4.6
MAX
11.4
– 11.1
3.0
4.75
200
– 6.3
0.8
UNITS
V
V
V
V
mV
V
V
V
µA
µA
µA
µA
µA
µA
mA
µA
µA
µA
µA
µA
mA
V
Ω
Ω
Ω
Ω
V
V
V
V
3VONLY
V
NOVEEIN
V
IL
V
IH
I
IN
3V Only Window Voltage
No V
EEIN
Threshold Voltage
Input Low Voltage
Input High Voltage
OFF/ON, RESETIN Input Current
RESETOUT, FAULT Output Current
PWRGD Output Current
5V
SENSE
Input Current
3V
SENSE
Input Current
5V
IN
Input Current
3V
IN
Input Current
5V
OUT
Input Current
3V
OUT
Input Current
±0.08
±0.08
±0.08
±0.08
55
55
1
490
380
102
161
–15
30
0.5
– 21
45
1
45
60
430
625
0.95
0.95
1.00
1.00
±10
±10
±10
±10
100
100
1.5
625
550
400
500
–27
70
1.3
100
100
1000
1000
0.4
1.05
1.05
I
TIMER
V
TIMER
R
DIS
TIMER Pin Current
TIMER Threshold Voltages
5V
OUT
Discharge Impedance
3V
OUT
Discharge Impedance
12V
OUT
Discharge Impedance
V
EEOUT
Discharge Impedance
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.
1644f
3
LTC1644
TYPICAL PERFOR A CE CHARACTERISTICS
3.3V and 5V Current Foldback
Profile
11
10
9
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
0.7
0.6
0.5
0.4
0.3
0.2
7
6
5
4
3
2
1
0
0
1
2
3
4
OUTPUT VOLTAGE (V)
5
1644 G01
OUTPUT CURRENT (A)
8
3V
OUT
5V
OUT
T
A
= 25°C
R
SENSE
= 0.005Ω
12V
IN
Supply Current
vs Temperature
3.2
12V
IN
UNDERVOLTAGE LOCKOUT (V)
12V
IN
SUPPLLY CURRENT (mA)
5V
IN
UVLO THRESHOLD VOLTAGE (V)
3.1
3.0
2.9
2.8
–50
–25
50
25
0
TEMPERATURE (°C)
3V
IN
UVLO Threshold Voltage
vs Temperature
5V FOLDBACK CURRENT LIMIT VOLTAGE (mV)
2.56
TIMER = 0V
3V FOLDBACK CURRENT LIMIT VOLTAGE (mV)
3V
IN
UVLO THRESHOLD VOLTAGE (V)
2.55
2.54
2.53
2.52
2.51
2.50
2.49
2.48
–25
RAMPING
UP
RAMPING
DOWN
2.47
–50
0
25
50
TEMPERATURE (°C)
4
U W
75
100
1644 G04
12V Output Current
1.0
0.9
0.8
0.30
0.25
0.20
0.15
0.10
0.05
0
0
2
4
6
8
OUTPUT VOLTAGE (V)
10
12
1644 G02
– 12V Output Current
0.40
0.35
T
A
= 25°C
V
EEIN
= –12V
T
A
= 25°C
12V
IN
= 12V
0.1
0
0
–2
–4
–6
–8
OUTPUT VOLTAGE (V)
–10
–12
1644 G03
12V
IN
Undervoltage Lockout
vs Temperature
8.50
8.45
8.40
8.35
8.30
8.25
8.20
–50
RAMPING
UP
2.55
2.54
2.53
2.52
2.51
2.50
2.49
2.48
2.47
5V
IN
UVLO Threshold Voltage
vs Temperature
RAMPING
UP
RAMPING
DOWN
RAMPING
DOWN
–25
25
50
0
TEMPERATURE (°C)
75
100
1644 G05
2.46
–50
–25
50
25
TEMPERATURE (°C)
0
75
100
1644 G06
5V Foldback Current Limit Voltage
vs Temperature
60
50
40
30
20
5V
OUT
= 0V
10
0
–50
60
50
40
30
20
5V
OUT
= 3V
3V Foldback Current Limit Voltage
vs Temperature
TIMER = 0V
3V
OUT
= 2V
3V
OUT
= 0V
10
0
–50
75
100
–25
0
25
50
TEMPERATURE (°C)
75
100
1644 G08
–25
0
25
50
TEMPERATURE (°C)
75
100
1644 G09
1644 G07
1644f
LTC1644
TYPICAL PERFOR A CE CHARACTERISTICS
5V/3.3V Circuit Breaker Trip
Voltage vs Temperature
5V/3.3V CIRCUIT BREAKER TRIP VOLTAGE (mV)
56.2
56.0
55.8
55.6
55.4
55.2
55.0
47.5
47.0
46.5
46.0
45.5
45.0
44.5
–50
5V/3.3V CIRCUIT BREAKER SHORT-CIRCUIT
RESPONSE TIME (µs)
5V/3.3V CIRCUIT BREAKER OVERCURRENT
FAULT RESPONSE TIME (µs)
TIMER PIN FLOATING
54.8
–50
–25
50
25
0
TEMPERATURE (°C)
GATE Pin Current vs Temperature
(V
GATE
= 2V, FAULT = 0V)
16
14
GATE PIN CURRENT (mA)
V
GATE
= 2V
FAULT = 0V
GATE PIN CURRENT (µA)
GATE PIN CURRENT (A)
12
10
8
6
4
2
0
–50
–25
50
25
TEMPERATURE (°C)
0
75
100
1644 G13
GATE Pin Voltage vs Temperature
V
CC
INTERNAL SWITCH VOLTAGE DROP (V)
11.97
0.30
0.25
0.20
0.15
0.10
0.05
0
–50
11.96
11.95
11.94
11.93
V
EE
INTERNAL SWITCH VOLTAGE DROP (V)
I
GATE
= –1µA
GATE PIN VOLTAGE (V)
11.92
–50
–25
50
25
0
TEMPERATURE (°C)
U W
75
100
1644 G10
5V/3.3V Circuit Breaker Overcurrent
Fault Response Time
vs Temperature
48.0
0.125
5V/3.3V Circuit Breaker Short-
Circuit Response Time
vs Temperature
0.120
0.115
0.110
0.105
–25
50
25
0
TEMPERATURE (°C)
75
100
1644 G11
0.100
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1644 G12
GATE Pin Current vs Temperature
(V
GATE
= 5V, OFF/ON = 4V)
300
250
–50
–55
–60
–65
–70
–75
–80
0
–50
–25
50
25
0
TEMPERATURE (°C)
75
100
1644 G14
GATE Pin Current vs Temperature
(V
GATE
= 0V, OFF/ON = 0V)
–40
–45
V
GATE
= 5V
OFF/ON = 4V
V
GATE
= 5V
OFF/ON = 4V
200
150
100
50
–85
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1644 G15
12V Internal Switch Voltage Drop
vs Temperature
0.35
I = 500mA
0.18
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
V
EE
Internal Switch Voltage Drop
vs Temperature
I
EE
= 100mA
75
100
1644 G16
–25
50
25
0
TEMPERATURE (°C)
75
100
1644 G17
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1644 G18
1644f
5
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