LTC1646
CompactPCI Dual
Hot Swap Controller
DESCRIPTIO
The LTC
®
1646 is a Hot Swap
TM
controller that allows a
board to be safely inserted and removed from a live
CompactPCI bus slot. Two external N-Channel transistors
control the 3.3V and 5V supplies. The supplies can be
ramped-up in current limit or a programmable rate. Elec-
tronic circuit breakers protect both supplies against
overcurrent fault conditions. 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 logically combined on-chip with HEALTHY#
in order to generate LOCAL_PCI_RST# which can be used
to reset the CPCI card logic if either of the supply voltages
is not within tolerance.
The LTC1646 is available in the 16-pin narrow SSOP
package.
FEATURES
■
■
■
■
■
■
■
■
■
Allows Safe Board Insertion and Removal from a
Live, CompactPCI
TM
Bus
Controls 3.3V and/or 5V Supplies
Programmable Foldback Current Limit During
Power-Up
Dual Level Circuit Breakers Protect Supplies from
Overcurrent and Short-Circuit Faults
LOCAL_PCI_RST# Logic On-Chip
PRECHARGE Output Biases I/O Pins During Card
Insertion and Extraction
User Programmable Supply Voltage Power-Up Rate
15V High Side Drive for External N-Channel
MOSFETS
PWRGD, RESETOUT and FAULT Outputs
APPLICATIO S
■
CompactPCI Bus Removable Boards
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
COMPACT PCI
BACKPLANE
CONNECTOR
(MALE)
5V
COMPACT PCI
CIRCUIT CARD
CONNECTOR
(FEMALE)
2.7Ω
Z1
Z2
R2
0.007Ω
1%
R1
0.005Ω, 1%
Q2
IRF7413
Q1
IRF7413
LONG 5V
3.3V
1.8Ω
LONG 3.3V
V(I/O)
0.1µF
0.1µF
R3
10Ω
8
3V
IN
9
10
7
3V
SENSE
GATE 3V
OUT
12
5V
IN
11
5V
SENSE
1.2k
BD_SEL#
V(I/O)
3k
HEALTHY#
PCI_RST#
3k
1k
15
3
4
16
OFF/ON
FAULT
LTC1646
PWRGD
RESETIN
GND
6
PRECHARGE
13
18Ω
4.7nF
18Ω
DRIVE
14
1k
12Ω
LOCAL_PCI_RST#
GROUND
10k
10Ω
I/O PIN 1
DATA BUS
Z1, Z2: BZX84C6V2
PRECHARGE OUT
1V
±10%
I
OUT
=
±
55mA
MMBT2222A
3V
IN
DATA LINE EXAMPLE
DATA BUS
Figure 1
U
U
U
5V
5A
3.3V
7.6A
R4
10Ω
5
5V
OUT
TIMER
2
R5
1k, 5%
C1
0.01µF
10k
0.1µF
3V
OUT
3k
RESETOUT
1
3V
IN
3.3V
RESET#
I/O
5V
IN
5V
PCI
BRIDGE
(21154)
1646 F01
1646fa
1
LTC1646
ABSOLUTE
(Note 1)
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
RESETOUT 1
TIMER 2
FAULT 3
PWRGD 4
5V
OUT
5
GND 6
3V
OUT
7
3V
IN
8
16 RESETIN
15 OFF/ON
14 DRIVE
13 PRECHARGE
12 5V
IN
11 5V
SENSE
10 GATE
9
3V
SENSE
Supply Voltages: 5V
IN
, 3V
IN ...............................................
10V
Input Voltages: (Pins 15, 16) ..................... –0.3V to 10V
Output Voltages: (Pins 1, 3, 4) .................. –0.3V to 10V
Analog Voltages and Currents:
(Pin 9) .................................... –0.3V to (3V
IN
+ 0.3V)
(Pins 2, 5, 7, 11, 13, 14) ........ –0.3V to (5V
IN
+ 0.3V)
(Pin 10) ..........................................................
±20mA
Operating Temperature Range:
LTC1646C ............................................... 0°C to 70°C
LTC1646I .............................................–40°C to 85°C
Storage Temperature Range ..................–65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
GN PACKAGE
16-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 135°C/W
ORDER PART NUMBER
LTC1646CGN
LTC1646IGN
GN PART MARKING
1646
1646I
Order Options
Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
5VIN
= 5V and V
3VIN
= 3.3V unless otherwise noted.
SYMBOL
I
DD
V
LKO
V
FB
PARAMETER
V
5VIN
Supply Current
Undervoltage Lockout
Foldback Current Limit Voltage
CONDITIONS
OFF/ON = 0V
5V
IN
3V
IN
V
FB
= (V
5VIN
– V
5VSENSE
), V
5VOUT
= 0V, TIMER = 0V
V
FB
= (V
5VIN
– V
5VSENSE
), V
5VOUT
= 4V, 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
), V
5VOUT
= 5V, TIMER Open
V
CB
= (V
3VIN
– V
3VSENSE
), V
3VOUT
= 3.3V, TIMER Open
(V
5VIN
– V
5VSENSE
) = 100mV, TIMER Open
(V
3VIN
– V
3VSENSE
) = 100mV, TIMER Open
(V
5VIN
– V
5VSENSE
) = 200mV, TIMER Open
(V
3VIN
– V
3VSENSE
) = 200mV, TIMER Open
OFF/ON = 0V, V
GATE
= 0V, TIMER = 0V
OFF/ON = 5V, V
GATE
= 5V, TIMER = 0V
OFF/ON = 0V, V
GATE
= 5V, FAULT = 0V, TIMER Open
OFF/ON = 0V, I
GATE
= –1µA
OFF/ON = 0V, V
5VIN
= 3.3V, I
GATE
= –1µA
3V
OUT
5V
OUT
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
ELECTRICAL CHARACTERISTICS
MIN
2.3
2.3
15
50
15
50
50
50
10
10
TYP
1.5
2.50
2.55
20
55
20
55
56
56
21
21
0.145
0.145
MAX
4
2.7
2.7
30
65
30
65
65
65
30
30
1
1
–8
300
12
16
15
3.0
4.75
200
0.8
UNITS
mA
V
V
mV
mV
mV
mV
mV
mV
µs
µs
µs
µs
µA
µA
mA
V
V
V
V
mV
V
1646fa
V
CB
t
OC
t
SS
I
CP
Circuit Breaker Trip Voltage
Overcurrent Fault Response Time
Short-Circuit Fault Response Time
GATE Pin Output Current
–18
80
4
12
11
2.8
4.5
50
–13
200
7
15
13
2.9
4.65
120
V
GATE
V
TH
V
3VONLY
V
IL
External Gate Voltage
(GATE to GND)
Power Good Threshold Voltage
No 5V Input Mode Window Voltage V
3VONLY
=
⎪V
5VIN
– V
3VIN
⎪,
V
5VOUT
= V
3VOUT
= 3.3V
Input Low Voltage
OFF/ON, RESETIN, FAULT
2
U
W
U
U
W W
W
LTC1646
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
5VIN
= 5V and V
3VIN
= 3.3V unless otherwise noted.
SYMBOL
V
IH
V
TIMER
I
IN
PARAMETER
Input High Voltage
TIMER Threshold Voltage
OFF/ON Input Current
RESETIN Input Current
5V
SENSE
Input Current
3V
SENSE
Input Current
3V
IN
Input Current
5V
OUT
Input Current
3V
OUT
Input Current
I
TIMER
R
DIS
V
OL
V
PXG
TIMER Pin Current
5V
OUT
Discharge Impedance
3V
OUT
Discharge Impedance
Output Low Voltage
PRECHARGE Reference Voltage
CONDITIONS
OFF/ON, RESETIN, FAULT
V
TIMER
, FAULT = 0V
OFF/ON = 5V
OFF/ON = 0V
RESETIN = 5V
RESETIN = 0V
5V
SENSE
= 5V, 5V
OUT
= 0V
3V
SENSE
= 3.3V, 3V
OUT
= 0V
3V
IN
= 3.3V
5V
OUT
= 5V, OFF/ON = 0V
3V
OUT
= 3.3V, OFF/ON = 0V
OFF/ON = 0V, V
TIMER
= 0V
OFF/ON = 5V, V
TIMER
= 5V
OFF/ON = 5V
OFF/ON = 5V
FAULT, PWRGD, RESETOUT, I = 2mA
V
PRECHARGE
, V
5VIN
= 5V and 3.3V
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
ELECTRICAL CHARACTERISTICS
MIN
2
1.15
TYP
1.25
±0.08
±0.08
±0.08
±0.08
66
66
460
0.9
0.9
MAX
1.35
±10
±10
±10
±10
100
100
1000
1.5
1.5
–3
220
220
0.4
1.10
UNITS
V
V
µA
µA
µA
µA
µA
µA
µA
mA
mA
µA
mA
Ω
Ω
V
V
–7
–5
6.6
120
120
0.25
0.90
1.00
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 PERFOR A CE CHARACTERISTICS
5V Current Foldback Profile
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
R
SENSE
= 0.007Ω
3
2
4
OUTPUT VOLTAGE (V)
5
1646 G01
8
7
6
5
4
3
2
1
0
0
1
R
SENSE
= 0.005Ω
3
2
OUTPUT VOLTAGE (V)
4
5
1646 G02
SUPPLY CURRENT (mA)
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
U W
3.3V Current Foldback Profile
12
11
10
9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
5V
IN
Supply Current vs
Temperature
1.0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G03
1646fa
3
LTC1646
TYPICAL PERFOR A CE CHARACTERISTICS
5V
IN
Undervoltage Lockout
Voltage vs Temperature
2.60
UNDERVOLTAGE LOCKOUT VOLTAGE (V)
UNDERVOLTAGE LOCKOUT VOLTAGE (V)
LOW-TO-HIGH TRANSITION
FOLDBACK CURRENT LIMIT VOLTAGE (mV)
2.55
LOW-TO-HIGH TRANSITION
2.50
HIGH-TO-LOW TRANSITION
2.45
2.40
–50
–25
0
25
50
TEMPERATURE (°C)
3V
IN
Foldback Current Limit
Voltage vs Temperature
60
FOLDBACK CURRENT LIMIT VOLTAGE (mV)
CIRCUIT BREAKER TRIP VOLTAGE (mV)
50
40
30
20
10
0
–50
3V
OUT
= 0V
3V
OUT
= 2V
60
59
58
57
56
55
54
53
52
51
CIRCUIT BREAKER TRIP VOLTAGE (mV)
–25
0
25
50
TEMPERATURE (°C)
5V
IN
/3V
IN
Overcurrent Fault
Response Time vs Temperature
21.75
21.50
21.25
21.00
20.75
20.50
20.25
20.00
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G10
SHORT-CIRCUIT FAULT RESPONSE TIME (ns)
OVERCURRENT FAULT RESPONSE TIME (µs)
22.00
GATE CURRENT (µA)
4
U W
75
75
3V
IN
Undervoltage Lockout
Voltage vs Temperature
2.60
60
50
40
30
20
10
5V
IN
Foldback Current Limit
Voltage vs Temperature
5V
OUT
= 4V
2.55
HIGH-TO-LOW TRANSITION
2.50
5V
OUT
= 0V
2.45
100
1646 G04
2.40
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G05
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G06
5V
IN
Circuit Breaker Trip Voltage
vs Temperature
60
59
58
57
56
55
54
53
52
51
3V
IN
Circuit Breaker Trip Voltage
vs Temperature
100
1646 G07
50
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G08
50
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G09
5V
IN
/3V
IN
Short-Circuit Fault
Response Time vs Temperature
170
160
–11
150
140
130
120
110
100
–50
–10
Gate Current vs Temperature
–12
–13
–14
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G11
–15
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G12
1646fa
LTC1646
TYPICAL PERFOR A CE CHARACTERISTICS
Gate I
SINK
vs Temperature
10
FAULT = 0V
9
GATE VOLTAGE (V)
GATE I
SINK
(mA)
15.0
14.5
14.0
13.5
5V
IN
= 3.3V
6
13.0
12.5
–50
15.5
I = –1µA
5V
IN
= 5V
POWER GOOD THRESHOLD VOLTAGE (V)
75
100
1646 G14
8
7
5
–50
–25
0
25
50
TEMPERATURE (°C)
Power Good Threshold Voltage vs
Temperature (5V
OUT
)
4.75
POWER GOOD THRESHOLD VOLTAGE (V)
TIMER THRESHOLD VOLTAGE (V)
1.30
4.70
1.28
5V
SENSE
INPUT CURRENT (µA)
4.65
4.60
4.55
4.50
–50
–25
0
25
50
TEMPERATURE (°C)
3V
SENSE
Input Current vs
Temperature
70
69
3V
SENSE
INPUT CURRENT (µA)
3V
IN
INPUT CURRENT (µA)
68
67
66
65
64
63
62
61
60
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G19
470
465
460
455
450
445
–50
TIMER CURRENT (µA)
U W
75
1646 G13
Gate Voltage vs Temperature
3.00
Power Good Threshold Voltage vs
Temperature (3V
OUT
)
2.95
2.90
2.85
100
–25
0
25
50
TEMPERATURE (°C)
2.80
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G15
Timer Threshold Voltage vs
Temperature
70
69
68
67
66
65
64
63
62
61
5V
SENSE
Input Current vs
Temperature
1.26
1.24
1.22
75
100
1646 G16
1.20
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G17
60
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G18
3V
IN
Input Current vs Temperature
480
475
–4.00
–4.25
–4.50
–4.75
–5.00
–5.25
–5.50
–5.75
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G20
Timer Current vs Temperature
–6.00
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1646 G21
1646fa
5
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