LTC1643AL
LTC1643AL-1/LTC1643AH
PCI-Bus Hot Swap
Controller
FEATURES
s
s
DESCRIPTIO
s
s
s
s
s
s
s
Allows Safe Board Insertion and Removal from a
Live PCI Slot
Works on either a Motherboard (LTC1643AH) or
CompactPCI
TM
Card (LTC1643AL/LTC1643AL-1)
Controls –12V, 3.3V, 5V, 12V Supplies
Programmable Foldback Current Limit with
Circuit Breaker
User-Programmable Supply Voltage Power-Up Rate
High Side Drive for External N-Channel MOSFETs
–12V and 12V On-Chip Switches
Fault and Power-Good Outputs
Available in a Narrow 16-Lead SSOP Package
APPLICATIO S
s
s
PCI-Based Servers
CompactPCI Compliant Boards
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
CompactPCI is a trademark of PCI Industrial Computer Manufacturing Group.
The LTC
®
1643A is a Hot Swap
TM
controller that allows a board
to be safely inserted and removed from a live PCI-Bus slot.
Two external N-channel transistors control the 3.3V and 5V
supplies while on-chip switches control the –12V and 12V
supplies. All supply voltages can be ramped up at a program-
mable rate. An electronic circuit breaker protects all four
supplies against overcurrent faults. The foldback current limit
feature limits current spikes and power dissipation when
shorts occur and allows boards with large capacitances to be
powered up without tripping the circuit breaker. The PWRGD
output indicates when all of the supply voltages are within
tolerance and the FAULT output indicates an overcurrent
condition. The ON(LTC1643AH)/ON (LTC1643AL/
LTC1643AL-1) pin is used to cycle the board power or reset
the circuit breaker. The LTC1643AL-1 has the
±12V
power
good comparators disabled.
The LTC1643A is available in a 16-pin narrow SSOP package.
TYPICAL APPLICATION
Hot Swappable PCI Supply
R1
0.007Ω
Q1
IRF7413
5V
5A
R2
0.005Ω
Q2
IRF7413
R6
10Ω
SYSTEM
POWER
SUPPLY
9
3V
IN
GND
1
12V
IN
2
V
EEIN
5
ON
8
PCI
POWER
SYSTEM
CONTROLLER
RESET
R3
10k
R4
10k
6
10
R5
10Ω
11
3
13
12
5V
SENSE
14
5V
OUT
R7
100Ω
C1
0.047µF
3V
SENSE
GATE
3V
OUT
5V
IN
12V
OUT
LTC1643AH
V
EEOUT
FAULT
TIMER
7
PWRGD
U
3.3V
7.6A
GND
16
15
4
C2
0.1µF
12V
500mA
–12V
100mA
LOGIC
RESET
1643A TA01
U
U
1643afa
1
LTC1643AL
LTC1643AL-1/LTC1643AH
ABSOLUTE
MAXIMUM
RATINGS
(Note 1)
PACKAGE/ORDER INFORMATION
ORDER PART NUMBER
TOP VIEW
12V
IN
1
V
EEIN
2
3V
OUT
3
TIMER 4
ON/ON* 5
FAULT 6
PWRGD 7
GND 8
16 12V
OUT
15 V
EEOUT
14 5V
OUT
13 5V
IN
12 5V
SENSE
11 GATE
10 3V
SENSE
9
3V
IN
Supply Voltages
12V
IN
................................................................ 13.2V
V
EEIN
.............................................................. –13.2V
Input Voltage (Pin 5) ................ – 0.3V to (12V
IN
+ 0.3V)
Output Voltages (Pins 6, 7) ...... – 0.3V to (12V
IN
+ 0.3V)
Analog Voltages
(Pins 3, 4, 9, 10 to 14) ........ – 0.3V to (12V
IN
+ 0.3V)
V
EEOUT
............................................ –13.2V to + 0.3V
12V
OUT
.............................................. – 0.3V to 13.2V
Operating Temperature Range
LTC1643ALC/LTC1643AL-1C/
LTC1643AHC ........................................... 0°C to 70°C
LTC1643ALI/LTC1643AL-1I/
LTC1643AHI ...................................... – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
LTC1643AHCGN
LTC1643ALCGN
LTC1643AL-1CGN
LTC1643AHIGN
LTC1643ALIGN
LTC1643AL-1IGN
GN PART MARKING
1643AH
1643AL
643AL1
643AHI
643ALI
43AL1I
GN PACKAGE
16-LEAD NARROW PLASTIC SSOP
*ON FOR LTC1643AH,
ON FOR LTC1643AL/LTC1643AL-1
T
JMAX
= 150°C,
θ
JA
= 135°C/ W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
DC ELECTRICAL CHARACTERISTICS
The
SYMBOL
I
DD
V
LKO
PARAMETER
V
12VIN
Supply Current
Undervoltage Lockout
CONDITIONS
ON = GND, ON = 3V
12V
IN
3V
IN
5V
IN
denotes specifications which apply over the full operating
temperature range, otherwise specifications are TA = 25°C. V
12VIN
= 12V, V
EEIN
= – 12V, V
3VIN
= 3.3V, V
5VIN
= 5V (Note 2)
q
MIN
q
q
q
q
q
q
q
q
TYP
3.5
9.5
2.5
2.5
7.5
53
7.5
53
14.6
– 62
200
17.5
100
225
225
125
MAX
8
10.8
2.75
2.75
12
65
12
65
– 100
UNITS
mA
V
V
V
mV
mV
mV
mV
µs
µA
µA
mA
mV
mV
mV
mA
mA
mA
mA
°C
V
V
V
V
1643afa
7
2.25
2.25
4
40
4
40
– 20
3
V
FB
Foldback Current Limit Voltage
V
FB
= (V
5VIN
– V
5VSENSE
), V
5VOUT
= 0V
V
FB
= (V
5VIN
– V
5VSENSE
), V
5VOUT
> 4V
V
FB
= (V
3VIN
– V
3VSENSE
), V
3VOUT
= 0V
V
FB
= (V
3VIN
– V
3VSENSE
), V
3VOUT
> 2V
Charge Pump On, V
GATE
= GND, FAULT = High
Charge Pump Off, V
GATE
= 5V, FAULT = High
Charge Pump Off, V
GATE
= 2V, FAULT = Low
(V
12VIN
– V
GATE
)
(V
12VIN
– V
12VOUT
),
I
12VOUT
= 500mA
(V
EEOUT
– V
EEIN
), I
VEEIN
= 100mA
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
t
CB
I
CP
Circuit Breaker Trip Filter Time
GATE Pin Output Current
q
q
∆V
GATE
V
DROP
External Gate Voltage
Internal Switch Voltage Drop
200
600
750
250
600
1500
500
800
11.4
11.4
– 10.8
– 10.8
q
q
q
q
q
q
q
I
CL
Current Foldback
12V
IN
= 12V, 12V
OUT
= 0V
12V
IN
= 12V, 12V
OUT
= 10V
V
EEIN
= –12V, V
EEOUT
= 0V (LTC1643AL/LTC1643AH Only)
V
EEIN
= –12V, V
EEOUT
= – 10V
V
12VOUT
LTC1643AH/LTC1643AL Only
V
EEOUT
LTC1643AH/LTC1643AL Only
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
50
525
50
225
10.8
10.4
– 10.2
– 10.0
250
850
160
450
150
11.1
11.1
– 10.5
– 10.5
T
TS
V
TH
Thermal Shutdown Temperature
Power-Good Threshold Voltage
q
q
q
q
2
U
W
U
U
W W
W
LTC1643AL
LTC1643AL-1/LTC1643AH
DC
ELECTRICAL CHARACTERISTICS
The
q
denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.
V
12VIN
= 12V, V
EEIN
= – 12V, V
3VIN
= 3.3V, V
5VIN
= 5V (Note 2)
SYMBOL
V
TH
PARAMETER
Power-Good Threshold Voltage
CONDITIONS
V
3VOUT
V
5VOUT
V
IL
V
IH
V
OL
I
IN
Input Low Voltage
Input High Voltage
Output Low Voltage
ON/ON Pin Input 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
R
DIS
5V
OUT
Discharge Impedance
3V
OUT
Discharge Impedance
12V
OUT
Discharge Impedance
V
EEOUT
Discharge Impedance
TIMER Pin Current
TIMER Threshold Voltage
ON/ON, FAULT
ON/ON, FAULT
FAULT, PWRGD, I = 3mA
ON/ON = GND
ON/ON= 12V
IN
5V
SENSE
= 5V
3V
SENSE
= 3V
5V
IN
= 5V
3V
IN
= 3V
5V
OUT
= 5V, ON = 3V, ON = GND
3V
OUT
= 3.3V, ON = 3V, ON = GND
ON = GND or ON = 3V
ON = GND or ON = 3V
ON = GND or ON = 3V
ON = GND or ON = 3V
Timer On, V
TIMER
= GND
Timer Off, V
TIMER
= 5V
(V
12VIN
– V
TIMER
)
q
MIN
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
TYP
2.9
2.9
4.65
4.65
MAX
3.0
3.0
4.75
4.75
0.8
UNITS
V
V
V
V
V
V
V
µA
µA
µA
µA
µA
µA
µA
µA
Ω
Ω
Ω
Ω
2.8
2.75
4.5
4.4
2
0.4
±
0.08
±
0.08
50
50
460
320
240
220
100
70
450
1600
– 15
0.5
– 22
45
0.9
– 27
1.3
±10
±10
100
100
700
600
500
500
I
TIMER
V
TIMER
µA
mA
V
q
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.
TYPICAL PERFORMANCE CHARACTERISTICS
3.3V and 5V Current
Foldback Profile
11
10
9
OUTPUT CURRENT (A)
7
6
5
4
3
2
1
0
0
1
5V
OUT
0.5
OUTPUT CURRENT (A)
8
OUTPUT CURRENT (A)
3V
OUT
R
SENSE
= 0.005Ω
0
3
4
2
OUTPUT VOLTAGE (V)
5
1643A G01
U W
12V Current Foldback Profile
1.0
1.0
– 12V Current Foldback Profile
0.5
0
2
6
8
4
OUTPUT VOLTAGE (V)
10
12
1643A G02
0
0
–2
–6
–8
–10
–4
OUTPUT VOLTAGE (V)
–12
1643A G03
1643afa
3
LTC1643AL
LTC1643AL-1/LTC1643AH
TYPICAL PERFORMANCE CHARACTERISTICS
Timer Current vs Temperature
23.5
23.0
TIMER CURRENT (µA)
22.0
21.5
21.0
20.5
20.0
19.5
–50 –25
0
25
50
75
100
125
GATE I
SINK
(mA)
20.0
17.5
15.0
12.5
10.0
–50 –25
GATE CURRENT (µA)
22.5
TEMPERATURE (°C)
1643A G04
Power Good Threshold Voltage vs
Temperature (12V
OUT
)
11.14
POWER GOOD THRESHOLD VOLTAGE (V)
POWER GOOD THRESHOLD VOLTAGE (V)
POWER GOOD THRESHOLD VOLTAGE (V)
11.12
11.10
11.08
11.06
11.04
–50 –25
50
0
75
25
TEMPERATURE (°C)
Power Good Threshold Voltage
vs Temperature (V
EEOUT
)
–10.58
325
POWER GOOD THRESHOLD VOLTAGE (V)
–10.56
–10.54
–10.52
–10.50
–10.48
–10.46
–10.44
–10.42
–50 –25
0
25
50
75
100
125
INTERNAL SWITCH VOLTAGE DROP (mV)
300
275
250
225
200
175
150
–50 –25
INTERNAL SWITCH VOLTAGE DROP (mV)
TEMPERATURE (°C)
1643A G10
4
U W
100
1643A G07
Gate I
SINK
vs Temperature
25.0
FAULT = LOW
22.5
80
90
Gate Current vs Temperature
70
60
50
50
25
75
0
TEMPERATURE (°C)
100
125
40
–50 –25
50
0
75
25
TEMPERATURE (°C)
100
125
1643A G05
1643A G06
Power Good Threshold Voltage vs
Temperature (5V
OUT
)
4.68
4.67
4.66
4.65
4.64
4.63
4.62
–50 –25
2.904
2.903
2.902
2.901
2.900
2.899
2.898
2.897
Power Good Threshold Voltage vs
Temperature (3V
OUT
)
125
50
25
75
0
TEMPERATURE (°C)
100
125
2.896
–50 –25
0
25
50
75
100
125
TEMPERATURE (°C)
1643A G08
1643A G09
12V Internal Switch Voltage Drop
vs Temperature
I
12VOUT
= 500mA
180
160
140
120
100
80
V
EE
Internal Switch Voltage Drop
vs Temperature
I
VEEIN
= 100mA
50
25
75
0
TEMPERATURE (°C)
100
125
60
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
LT1643A
G11
1643A G12
1643afa
LTC1643AL
LTC1643AL-1/LTC1643AH
TYPICAL PERFORMANCE CHARACTERISTICS
Circuit Breaker Trip Filter Time
vs Temperature
15.50
CIRCUIT BREAKER TRIP FILTER TIME (µs)
15.25
15.00
14.75
14.50
14.25
14.00
–50 –25
TIMER THRESHOLD VOLTAGE (V)
1.0
12V
IN
SUPPLY CURRENT (mA)
50
25
75
0
TEMPERATURE (°C)
V
EEIN
Supply Current
vs Temperature
0.90
0.89
0.88
0.87
0.86
0.85
0.84
–50 –25
270
268
V
EEIN
SUPPLY CURRENT (mA)
5V
IN
SUPPLY CURRENT (µA)
266
264
262
260
258
256
–50 –25
3V
IN
SUPPLY CURRENT (µA)
50
25
75
0
TEMPERATURE (°C)
V
OL
vs Temperature
350
300
FAULT
250
I = 3mA
UNDERVOLTAGE LOCKOUT (V)
9.515
9.510
9.505
9.500
9.495
9.490
UNDERVOLTAGE LOCKOUT (V)
V
OL
(mV)
200
150
PWRGD
100
50
–50 –25
50
25
75
0
TEMPERATURE (°C)
U W
100
1643A G13
Timer Threshold Voltage
vs Temperature
V
12VIN
– V
TIMER
3.72
12V
IN
Supply Current
vs Temperature
3.70
0.9
3.68
3.66
0.8
3.64
125
0.7
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
3.62
–50 –25
50
75
0
25
TEMPERATURE (°C)
100
125
1643A G14
1643A G15
5V
IN
Supply Current
vs Temperature
275.0
272.5
270.0
267.5
265.0
262.5
3V
IN
Supply Current
vs Temperature
100
125
50
25
75
0
TEMPERATURE (°C)
100
125
260.0
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
1643A G16
LT1643A
G17
1643A G18
12V
IN
Undervoltage Lockout
vs Temperature
2.454
2.452
2.450
2.448
2.446
2.444
5V
IN
Undervoltage Lockout
vs Temperature
100
125
9.485
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
2.442
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
1643A G19
1643A G20
1643A G21
1643afa
5
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