Linear Technology LTC1647-2, LTC1647-1, LTC1647-3 Datasheet

5ms/DIV

2.5V/DIV

1647-1/2/3 TA01a

V

ON

V

GATE

V

OUT

FEATURES

LTC1647-1/LTC1647-2/LTC1647-3

Dual Hot Swap Controllers

U

DESCRIPTIO

■

Allows Safe Board Insertion and Removal from a
Live Backplane

■

Programmable Electronic Circuit Breaker

■

FAULT Output Indication

■

Programmable Supply Voltage Power-Up Rate

■

High Side Drive for External MOSFET Switches

■

Controls Supply Voltages from 2.7V to 16.5V

■

Undervoltage Lockout

U

APPLICATIO S

■

Hot Board Insertion

■

Electronic Circuit Breaker

■

Portable Computer Device Bays

■

Hot Plug Disk Drive

The LTC®1647-1/LTC1647-2/LTC1647-3 are dual Hot
SwapTM controllers that permit a board to be safely in­serted and removed from a live backplane.

Using external N-channel MOSFETs, the board supply
voltages can be ramped up at a programmable rate. A high
side switch driver controls the MOSFET gates for supply
voltages ranging from 2.7V to 16.5V. A programmable
electronic circuit breaker protects against overloads and
shorts. The ON pins are used to control board power or
clear a fault.

The LTC1647-1 is a dual Hot Swap controller with a
common VCC pin, separate ON pins and is available in an
SO-8 package. The LTC1647-2 is similar to the LTC1647-1
but combines a fault status flag with automatic retry at the
ON pins and is also available in the SO-8 package. The
LTC1647-3 has individual VCC pins, ON pins and FAULT
status pins for each channel and is available in a 16-lead
narrow SSOP package.

, LTC and LT are registered trademarks of Linear Technology Corporation.

Hot Swap is a trademark of Linear Technology Corporation.

TYPICAL APPLICATIO

3.3V V
SUPPLY

R1

ON1
ON2

0.1Ω

R5

0.1Ω

1
2
3
4

SENSE 1

V

CC

ON1
ON2
GND

SENSE 2

ID

Q1

1/2 MMDF3N02HD

R2
10Ω

86

GATE 1

LTC1647-1

GATE 2

75

R6
10Ω

Q2

1/2 MMDF3N02HD

U

VID Controller for Two Device Bays

DEVICE #1

R3** R4**C

C1

4.7nF

*C
** R3, R4, R7 AND R8 ARE OPTIONAL DISCHARGE

C3

4.7nF

R7** R8**C

+

CONNECTOR #1

IS USER-SELECTED BASED

LOAD

ON THE DEVICE REQUIREMENTS
RESISTORS WHEN DEVICES ARE POWERED-OFF

Q1, Q2: ON SEMICONDUCTOR

+

CONNECTOR #2

LOAD

DEVICE #2

LOAD

*

*

1394 PHY

AND/OR

USB PORT

1394 PHY

AND/OR

USB PORT

1647-1/2/3 TA01

ON/OFF Sequence

1

LTC1647-1/LTC1647-2/LTC1647-3

WW

W

U

ABSOLUTE AXI U RATI GS

(Note 1)

Supply Voltage (VCC) ............................................... 17V

Input Voltage (SENSE)................. –0.3V to (VCC + 0.3V)

Input Voltage (ON).....................................–0.3V to 17V

Output Voltage (FAULT).............................–0.3V to 17V

Output Voltage (GATE) ......... Internally Limited (Note 3)

UUW

PACKAGE/ORDER I FOR A TIO

TOP VIEW

V

1

CC

ON1

2

ON2

3

GND

4

8-LEAD PLASTIC SO

T

JMAX

8
7
6
5

S8 PACKAGE

= 150°C, θJA = 130°C/W

SENSE 1
SENSE 2
GATE 1
GATE 2

V
ON1/FAULT 1
ON2/FAULT 2

GND

T

1

CC

2
3
4

S8 PACKAGE

8-LEAD PLASTIC SO

= 150°C, θJA = 130°C/W

JMAX

Operating Temperature Range

Commercial .............................................0°C to 70°C

Industrial ............................................ –40°C to 85°C

Storage Temperature Range................. –65°C to 150°C

Lead Temperature (Soldering, 10 sec)..................300°C

1
2
3
4
5
6
7
8

TOP VIEW

16
15
14
13
12
11
10

9

V
SENSE 1
SENSE 2
GATE 1
GATE 2
NC
NC
NC

TOP VIEW

8
7
6
5

SENSE 1
SENSE 2
GATE 1
GATE 2

V

CC1

ON1

FAULT 1

ON2

FAULT 2

NC
NC

GND

CC2

GN PACKAGE

16-LEAD PLASTIC SSOP

T

= 150°C, θJA = 130°C/W

JMAX

ORDER PART NUMBER

LTC1647-1CS8
LTC1647-1IS8

S8 PART MARKING

16471
16471I

ORDER PART NUMBER

LTC1647-2CS8
LTC1647-2IS8

S8 PART MARKING

16472
16472I

ORDER PART NUMBER

LTC1647-3CGN
LTC1647-3IGN

GN PART MARKING

16473
16473I

Consult factory for Military grade parts.

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V unless otherwise noted. (Note 2)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V
I
I

V
V
V
I

CC
CC
CCX

LKO

LKH

CB
CP

V

Supply Range Operating Range ● 2.7 16.5 V

CCX

VCC Supply Current (Note 4) ON1, ON2 = V
V

Supply Current (Note 5, LTC1647-3) ONX = V

CCX

V

Undervoltage Lockout Coming Out of UVLO (Rising V

CCX

V

Undervoltage Lockout Hysteresis 210 mV

CCX

Circuit Breaker Trip Voltage VCB = V

V

CC1

= 5V, V

CCX

GATE X Output Current ONX High, FAULT X High, V

ONX Low, FAULT X High, V
ONX High, FAULT X Low, V

= V

, ICC = I

CC2

Individually Measured, ● 0.5 5 mA

= 12V or V

SENSEX

CCX

, I

CC2

– V

CC1
CCX

+ I

CC1

CC2

= 12V, V

CC1

CCX

= GND (Sourcing) ● 61014 µA

GATE

= VCC (Sinking) 50 µA

GATE

= 15V (Sinking) 50 mA

GATE

= 5V

CC2

) ● 2.30 2.45 2.60 V

● 1.0 6 mA

● 40 50 60 mV

2

LTC1647-1/LTC1647-2/LTC1647-3

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V unless otherwise noted. (Note 2)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

∆V

V

ONHI

V

ONLO

V

ONHYST

I

IN

V

OL

I

LEAK

t

FAULT

t

RESET

t

ON

t

OFF

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: An internal Zener on the GATE pins clamp the charge pump
voltage to a typical maximum operating voltage of 28V. External overdrive
of the GATE pin beyond the internal Zener voltage may damage the device.

External MOSFET Gate Drive (V

GATE

(V

GATE
GATE

– VCC), V
– VCC), V

CC1
CC1

= V

= 5V ● 10 13 17 V

CC2

= V

= 12V ● 10 15 19 V

CC2

ONX Threshold High ● 1.20 1.29 1.38 V
ONX Threshold Low ● 1.17 1.21 1.25 V
ONX Hysteresis 70 mV
ONX Input Current ON = GND or V

CC

● ±1 ±10 µA

FAULT X Output Low Voltage IO = 1mA, VCC = 5V ● 0.4 V
(LTC1647-2, LTC1647-3) I

= 5mA, VCC = 5V 0.8 V

O

FAULT X Output Leakage Current No Fault, FAULT X = VCC = 5V ±1 ±10 µA
(LTC1647-3)

Circuit Breaker Delay Time V

CCX

– V

= 0 to 100mV 0.3 µs

SENSEX

Circuit Breaker Reset Time ONX High to Low, to FAULT X High ● 50 100 µs
Turn-On Time ONX Low to High, to GATE X On 2 µs
Turn-Off Time ONX High to Low, to GATE X Off 1 µs

The GATE capacitance must be <0.15µF at maximum V

CC

pin clamp voltage is desired, use an external Zener diode.
Note 4: The total supply current I

is measured with V

CC

CC1

connected internally (LTC1647-1, LTC1647-2) or externally (LTC1647-3).
Note 5: The individual supply current I

The lower of the two supplies, V

CC1

is measured on the LTC1647-3.

CCX

and V

, will have its channel’s

CC2

current. The higher supply will carry the additional supply current of the
charge pump and the bias generator beside its channel’s current.

. If a lower GATE

and V

CC2

PIUTABLES

LTC1647-1 Pinout

PIN DESCRIPTION

1V

CC

2 ON1
3 ON2
4 GND

LTC1647-1 does not have the FAULT status feature.

LTC1647-2 Pinout

PIN DESCRIPTION

1V

CC

2 ON1 and FAULT 1

(Internally Tied Together)

3 ON2 and FAULT 2

(Internally Tied Together)

4 GND
The ONX/FAULT X must be connected to a driver via a resistor if the

autoretry feature is being used..

PIN DESCRIPTION

5 GATE 2
6 GATE 1
7 SENSE 2
8 SENSE 1

PIN DESCRIPTION

5 GATE 2
6 GATE 1
7 SENSE 2
8 SENSE 1

LTC1647-3 Pinout

PIN DESCRIPTION

1V

CC1

2 ON1
3 FAULT 1
4 ON2
5 FAULT 2
6NC
7NC
8 GND

PIN DESCRIPTION

9NC
10 NC
11 NC
12 GATE 2
13 GATE 1
14 SENSE 2
15 SENSE 1
16 V

CC2

3

LTC1647-1/LTC1647-2/LTC1647-3

UW

TYPICAL PERFOR A CE CHAR ACTERISTICS

ICC vs V

CC

6

TA = 25°C

= I

+ I

I

CC

CC1

5

VCC = V

4

3

(mA)

CC

I

2

1

0

2

I

vs V

CC2

5

TA = 25°C

4

3

(mA)

CC2

I

2

V

CC1

1

0

02468101214161820

CC2

= V

CC1

6 10 14 184 8 12 16

= ON1 = ON2

CC2

VCC (V)

CC2

V

= 15V

CC1

V

= 12V

CC1

= 3V

V

= 5V

CC1

V

(V)

CC2

1647-1/2/3 G01

1647-1/2/3 G04

ICC vs Temperature I

6

ICC = I

+ I

CC1

VCC = V

5

4

3

(mA)

CC

I

2

1

0

–75 –50 –25 0 25 50 75 100 125 150

(V

GATE

20
18
16
14

) (V)

12

CC

10

– V

8

GATE

(V

6
4
2
0

02468101214161820

CC2

= V

CC1

VCC = 15V VCC = 12V

VCC = 5V

– VCC) vs V

= ON1 = ON2

CC2

TEMPERATURE (°C)

CC

TA = 25°C

= V

V

CC

VCC (V)

CC1

VCC = 3V

1647-1/2/3 G02

= V

CC2

1647-1/2/3 G05

vs V

CC1

5

4

3

(mA)

CC1

I

2

1

0

02468101214161820

V

30

25

20

(V)

15

GATE

V

10

5

0

02468101214161820

TA = 25°C

V

CC1

vs V

GATE

CC2

= 15V

V

CC1

CC

V

= 5V

CC1

V

= 12V

CC1

V

VCC (V)

= 3V

CC2

(V)

TA = 25°C
V

CC

= V

CC1

1647-1/2/3 G03

= V

CC2

1647-1/2/3 G06

(V

– VCC) vs Temperature V

GATE

20
18
16
14

) (V)

12

CC

10

– V

8

GATE

(V

6
4
2
0

–75 –50 –25 0 25 50 75 100 125 150

VCC = 12V

VCC = 5V

VCC = 15V

TEMPERATURE (°C)

VCC = 3V

VCC = V

CC1

4

= V

CC2

1647-1/2/3 G07

vs Temperature (V

GATE

35

VCC = 15V

30

25

VCC = 5V

20

(V)

GATE

15

V

VCC = 3V

10

5

0

–75 –50 –25 0 25 50 75 100 125 150

TEMPERATURE (°C)

VCC = 12V

VCC = V

CC1

= V

CC2

1647-1/2/3 G08

– V

GATE1

20

V

18

CC1

16
14

) (V)

12

CC1

10

– V

8

GATE1

(V

6

V

4
2
0

02468101214161820

) vs Temperature

CC1

= 12V

V

= 5V

CC1

= 3V

CC1

V

CC2

(V)

V

CC1

= 15V

TA = 25°C
(LTC1647-3)

1647-1/2/3 G09

LTC1647-1/LTC1647-2/LTC1647-3

UW

TYPICAL PERFOR A CE CHAR ACTERISTICS

V

vs V

GATE1

35

V

30

25

V

20

(V)

GATE1

15

V

10

5

0

02468101214161820

CC1

CC1

= 15V

= 12V

CC2

V

= 5V

CC1

V

= 3V

CC1

TA = 25°C
(LTC1647-3)

V

(V)

CC2

GATE Output Sink Current vs V

100

TA = 25°C

90
80
70
60
50
40
30
20

GATE OUTPUT SINK CURRENT (µA)

10

0

02468101214161820

VCC (V)

1647-1/2/3 G10

CC

1647-1/2/3 G13

GATE Output Source Current vs
V

CC

14

TA = 25°C

13

= V

V

12
11
10

9
8
7

GATE OUTPUT SOURCE CURRENT (µA)

6

02468101214161820

=V

CC

CC1

CC2

VCC (V)

GATE Output Sink Current vs
Temperature

55

VCC = 5V

54
53
52
51
50
49
48
47

GATE OUTPUT SINK CURRENT (µA)

46
45

–75 –50 –25 0 25 50 75 100 125 150

TEMPERATURE (°C)

1647-1/2/3 G11

1647-1/2/3 G14

GATE Output Source Current vs
Temperature

14

VCC = V

13
12
11
10

9
8
7

GATE OUTPUT SOURCE CURRENT (µA)

6

–75 –50 –25 0 25 50 75 100 125 150

= V

= 5V

CC1

CC2

TEMPERATURE (°C)

GATE Fast Pull-Down Current vs
V

CC

60

TA = 25°C

55

50

45

40

35

GATE FAST PULL-DOWN CURRENT (mA)

30

02468101214161820

VCC (V)

1647-1/2/3 G12

1647-1/2/3 G15

GATE Fast Pull-Down Current vs
Temperature

80

VCC = V

70
60
50
40
30
20
10

GATE FAST PULL-DOWN CURRENT (mA)

0

–75 –50 –25 0 25 50 75 100 125 150

= V

CC1

= 5V

CC2

TEMPERATURE (°C)

1647-1/2/3 G16

Circuit Breaker Trip Voltage vs
V

CC

60

TA = 25°C

58
56
54
52
50
48
46
44
42

CIRCUIT BREAKER TRIP VOLTAGE (mV)

40

02468101214161820

VCC (V)

1647-1/2/3 G17

Circuit Breaker Trip Voltage vs
Temperature

60
58
56
54
52
50
48
46
44
42

CIRCUIT BREAKER TRIP VOLTAGE (mV)

40

–75 –50 –25 0 25 50 75 100 125 150

VCC = 15V

= 12V

V

CC

VCC = 5V

= 3V

V

CC

TEMPERATURE (°C)

1647-1/2/3 G18

5

LTC1647-1/LTC1647-2/LTC1647-3

UW

TYPICAL PERFOR A CE CHAR ACTERISTICS

Undervoltage Lockout Threshold
vs Temperature ON Threshold Voltage vs V

2.6

2.5

2.4

2.3

2.2

UNDERVOLTAGE LOCKOUT THRESHOLD (V)

2.1
–75 –50 –25 0 25 50 75 100 125 150

FAULT VOL vs V

2.0

TA = 25°C

1.8

1.6

1.4

(V)

1.2

OL

1.0

0.8

FAULT V

0.6

0.4

0.2

0

02468101214161820

RISING EDGE

FALLING EDGE

TEMPERATURE (°C)

CC

IOL = 5mA

IOL = 1mA

VCC (V)

1647-1/2/3 G19

1647-1/2/3 G22

1.35
TA = 25°C

1.30

1.25

1.20

ON THRESHOLD VOLTAGE (V)

1.15

02468101214161820

HIGH

LOW

VCC (V)

FAULT VOL vs Temperature T

2.0
VCC = 5V

1.8

1.6

1.4

(V)

1.2

OL

1.0

0.8

FAULT V

0.6

0.4

0.2

0

–75 –50 –25 0 25 50 75 100 125 150

IOL = 5mA

IOL = 1mA

TEMPERATURE (°C)

CC

1647-1/2/3 G20

1647-1/2/3 G23

ON Threshold Voltage vs
Temperature

1.35
VCC = 5V

1.30

1.25

1.20

ON THRESHOLD VOLTAGE (V)

1.15

–75 –50 –25 0 25 50 75 100 125 150

FAULT

1.0
TA = 25°C

0.8

0.6

(µs)

FAULT

T

0.4

0.2

0

02468101214161820

HIGH

LOW

TEMPERATURE (°C)

vs V

CC

VCC (V)

1647-1/2/3 G21

1647-1/2/3 G24

T

vs Temperature Circuit Breaker Reset Time vs V

FAULT

1.0

0.8

0.6

(µs)

FAULT

T

0.4

0.2

VCC = 3V

VCC = 5V

0

–75 –50 –25 0 25 50 75 100 125 150

TEMPERATURE (°C)

VCC = 12V

VCC = 15V

6

1647-1/2/3 G25

70

TA = 25°C

60

50

40

CIRCUIT BREAKER RESET TIME (µs)

30

02468101214161820

VCC (V)

CC

1647-1/2/3 G26

Circuit Breaker Reset Time vs
Temperature

60
58
56
54
52
50
48
46
44

CIRCUIT BREAKER RESET TIME (µs)

42
40

VCC = 3V

VCC = 5V

VCC = 12V

VCC = 15V

–75 –50 –25 0 25 50 75 100 125 150

TEMPERATURE (°C)

1647-1/2/3 G27