LINEAR TECHNOLOGY LT4220 Technical data

FEATURES

■

Hot SwapTM Controller for Positive
and Negative Supplies

■

Supply Tracking Mode

■

±2.7V to ±16.5V Operation

■

Analog Current Limit with Foldback

■

Allows Safe Board Insertion and Removal
from a Live Backplane

■

Open-Collector Power Good Comparators

■

Automatic Retry or Latchoff After a Current Fault

■

Dual Undervoltage Lockout Comparator Inputs

■

Current Fault Indication

U

APPLICATIO S

■

Live Board Insertion

■

RAID Systems

■

–5.2V ECL Supplies

■

Industrial Controls

■

Split Supply Systems

LT4220

Dual Supply

Hot Swap Controller

U

DESCRIPTIO

The LT®4220 16-pin dual voltage Hot Swap controller
allows a board to be safely inserted and removed from a
live backplane. The device operates with any combination
of 2.7V to 16.5V and –2.7V to –16.5V supplies. Using two
external N-channel pass transistors, the board supply
voltages can be ramped up at an adjustable rate. A select­able tracking mode allows dual supply tracking control for
ramping the positive and negative supplies together.

The LT4220 features foldback current limit and latches off
both gates if either supply remains in current limit longer
than an adjustable time period. The IC can be configured
for automatic restart after a delay set by the same timer.

A power good signal indicates when the output voltages
monitored by the two FB comparators are within tolerance,
and the gate drive signals are at their full on voltage.

The LT4220 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

±12V 10A Hot Swap Controller

+

12V
V

–12V

V

CC

EE

V

36.5k

4.99k

CONNECTOR 1

CONNECTOR 2

4.99k

36.5k

V

IN

R13

Z1*

R1

R2

R4

R3

–

IN

10Ω

C4
100nF

R15

20k

C7

10nF

10nF

C6

1µF

C8

Z2*

* 1SMA13AT3 TRANSIENT

VOLTAGE SUPPRESSOR

12

11

R14
10Ω

8

9

6

C5
1µF

U

TRACK

+

ON
FAULT
TIMER

GND

–

ON

V

R

S

0.005Ω

716

V

CC

LT4220

EE

SENSEK

12

R

S

0.005Ω

+

SUB85N03-04

R5

10Ω

15 14

+

SENSE

PWRGD

–

SENSE

GATE

34

C3

100nF

–

SUB85N03-04

Q1

GATE

Q2

12V

+

V

OUT

R10

R12

CL1

R9

36.5k

R11

36.5k

CL2

+

–12V
V

OUT

4220 TA01

12V

V

+

IN

12V

+

V

OUT

–12V

–

V

IN

–12V

V

–

OUT

TIME (10ms/DIV)

–

4220f

D1
IN4001

D2
IN4001

+

C1

R6

10nF

1k

+

10

R16, 20k

13

+

FB

4.99k

4.99k

5

–

FB

–

C2

R8

10nF

1k

R7
10Ω

1

LT4220

WW

W

U

ABSOLUTE MAXIMUM RATINGS

(Notes 1, 2)

VCC to GND ............................................................. 22V

VEE to GND ........................................................... –22V

TRACK, TIMER .............................. – 0.3V to VCC + 0.3V

ON+, FB+................................. V

ON–, FB–.................................. V

GATE+................................................ –0.3V to VCC + 8V

GATE–..............................–16.5V with VEE = –22V to 0V

SENSE+............................................. –0.3V to VCC + 5V

SENSE–, SENSEK ....................... VEE – 0.3V to V

PWRGD, FAULT ................................. –0.3V to VCC + 5V

Operating Temperature Range

LT4220C...........................................0°C ≤ TA ≤ 70°C

LT4220I ....................................... –40°C ≤ TA ≤ 85°C

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

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

– 0.3V to VCC + 0.3V

EE

– 0.3V to V

EE

CC

EE

+ 0.3V

+ 3V

U

W

U

PACKAGE/ORDER INFORMATION

TOP VIEW

1

V

EE

SENSEK
SENSE

Consult LTC Marketing for parts specified with wider operating temperature ranges.

2

–

3

–

4

GATE

–

5

FB

–

6

ON

7

TRACK

8

TIMER

16-LEAD PLASTIC SSOP

T

= 125°C, θJA = 130°C/W

JMAX

GN PACKAGE

16
15
14
13
12
11
10

9

V

CC

SENSE
GATE

+

FB

+

ON
FAULT
PWRGD
GND

+

+

ORDER PART

NUMBER

LT4220CGN
LT4220IGN

GN PART MARKING

4220
4220I

DC ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, VEE = –5V, unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

CC

I

CC

V

EE

I

EE

V

PLKO

V

MLKO

V

ON+H

V

ON+HYS

∆V

ON+H

∆V

ON–H

V

ON–HYS

V

ON–H

+

I

ON

–

I

ON

V

FB+H

V

FB+HYS

V

FB–H

V

FB–HYS

VCC Operating Range ● 2.7 16.5 V
VCC Supply Current ● 2.7 4 mA
VEE Operating Range ● –2.7 –16.5 V
VEE Supply Current –1.6 –2.4 mA
VCC Undervoltage Lockout ● 2.35 2.45 2.55 V
VEE Undervoltage Lockout ● –2.4 –2.45 –2.5 V
ON+ ON Threshold ON+ Rising ● 1.22 1.24 1.26 V
ON+ Hysteresis ● 25 50 70 mV
ON+ ON Threshold Line Regulation V
ON– ON Threshold Line Regulation V
ON– Hysteresis ● 25 50 70 mV
ON– ON Voltage Threshold ON– Falling ● –1.22 –1.24 –1.26 V
ON+ Input Current V
ON– Input Current V
FB+ PWRGD Voltage Threshold FB+ Rising ● 1.22 1.24 1.26 V
FB+ Hysteresis Gate = 5V ● 25 50 70 mV
FB– PWRGD Voltage Threshold FB– Falling ● –1.22 –1.24 –1.26 V
FB– Hysteresis Gate = 3V ● 25 50 70 mV

= 2.7V, V

CC

= 2.7V, V

CC

+

= 2V ● 0.01 ±1 µA

ON

–

= GND ● 0.01 ±1 µA

ON

= –2.7V to VCC = 16.5V, VEE = –16.5V ● 0.02 0.15 mV/V

EE

= –2.7V to VCC = 16.5V, VEE = –16.5V ● 0.05 1 mV/V

EE

2

4220f

LT4220

DC ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, VEE = –5V, unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

+

I

INFB

I

INFB

∆V
∆

VFB–H

V

SENSE

V

SENSE

I

GATEUP

I

GATEUP

I

GATEDN

I

GATEDN

∆V

∆V

V

TIMERH

V

TIMERL

I

TIMERUP

I

TIMERDN

I

TIMER(R)

V

OL

I

OH

V

FOL

I

FPH

V

TRKTHR

I

TRK

V

TRKFB

V

TRKFB

FB+ Input Current FB+ = 3V ● 0.09 ±1 µA

–

FB– Input Current FB– = –3V ● 0.08 ±1 µA
FB+ PWRGD Threshold Line Regulation V

FB+H

FB– PWRGD Threshold Line Regulation V

+

SENSE+ Trip Voltage (VCC – V

–

SENSE– Trip Voltage (V

+

GATE+ Pull-Up Current Charge Pump On, V

–

GATE– Pull-Up Current V

+

GATE+ Pull-Down Current Any Fault Condition, V

–

GATE– Pull-Down Current Any Fault Condition, V

+

External N-Channel GATE+ Drive V

GATE

–

External N-Channel GATE– Drive V

GATE

SENSEK

+

)V

SENSE

– V

SENSE

= 2.7V, V

CC

= 2.7V, V

CC

+

= 0V, GATE+ – 0.5V ● 61522 mV

FB

+

V

= 1V, GATE+ – 0.5V 36 48 60 mV

FB

–

–

)V

= 0V, GATE– – 0.5V ● –10 –15 –22 mV

FB

–

= –1V, GATE– – 0.5V –43 –52 –61 mV

V

FB

– = –3V ● –6 –10 –14 µA

GATE

+

– VCC, VCC = 2.7V, VEE = –2.7V ● 3.5 4 6 V

GATE

= 5V to 16.5V, VEE = –5V to –16.5V 5 6.5 8 V

V

CC

–

– VEE, VCC = 2.7V, VEE = –2.7V ● 3.5 5.2 6 V

GATE

= 5V to 16.5V, VEE = –5V to –16.5V 7.5 8.5 9 V

V

CC

= –2.7V to VCC = 16.5V, VEE = –16.5V ● 0.015 0.15 mV/V

EE

= –2.7V to VCC = 16.5V, VEE = –16.5V ● 0.05 0.5 mV/V

EE

+

= 7V ● –9 –13 –17 µA

GATE

+

= 1V ● 20 40 60 mA

GATE

–

= VEE + 4V ● 30 70 130 mA

GATE

TIMER High Threshold, Sets FAULT ● 1.22 1.24 1.26 V
TIMER Low Threshold, Allows Restart ● 0.4 0.5 0.6 V
TIMER Pull-Up Current TIMER = 0V ● –40 –65 –85 µA
TIMER Pull-Down Current TIMER = 1V ● 2 3.3 4.5 µA
TIMER Current Ratio I

TIMERDN/ITIMERUP

57 %

PWRGD Output Low Voltage IO = 2mA ● 0.3 V

= 5mA 0.5 V

I

O

PWRGD Leakage Current V

= 16.5V ● 0.1 2 µA

PWRGD

FAULT Output Low Voltage IO = 2mA ● 0.3 V

= 5mA 0.5 V

I

O

FAULT Leakage Current V

= 16.5V ● 0.06 2 µA

FAULT

TRACK Input Threshold ● 0.3 0.8 1.1 V
TRACK Input Current TRACK = 16.5V ● 0.05 2 µA

+

TRACK Mode FB+ Threshold I

–

TRACK Mode FB– Threshold I

+

= 0µA, TRACK = V

GATE

–

= 0µA, TRACK = V

GATE

(Note 3) ● 40 70 mV

CC

(Note 3) ● 40 80 mV

CC

4220f

3

LT4220

AC ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, VEE = –5V, unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

+

t

PHLON

t

PLHON

t

PHLFB

t

PLHFB

t

PHLON

t

PLHON

t

PHLFB

t

PLHFB

t

SENSE

t

SENSE

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

ON+ Low to GATE+ Low 5k Pull-Up to GATE+, 1nF Load Capacitor ● 0.6 0.8 1.2 µs

+

ON+ High to GATE+ High 5k Pull-Up to GATE+, 1nF Load Capacitor ● 0.6 1.5 3 µs

+

FB+ Low to PWRGD Low 5k Pull-Up to PWRGD ● 0.5 0.8 1.2 µs

+

FB+ High to PWRGD High 5k Pull-Up to PWRGD ● 0.6 1.25 3 µs

–

ON– Low to GATE– Low 5k Pull-Up to GATE–, 1nF Load Capacitor ● 0.6 1 1.5 µs

–

ON– High to GATE– High 5k Pull-Up to GATE–, 1nF Load Capacitor ● 1 2.1 3.5 µs

–

FB– Low to PWRGD Low 5k Pull-Up to PWRGD ● 0.6 1 1.5 µs

–

FB– High to PWRGD High 5k Pull-Up to PWRGD ● 0.8 1.25 2 µs

+

SENSE+ to GATE+ Low 1nF On GATE+, 100mV Step, 5k Pull-Up ● 146 µs

–

SENSE– to GATE– Low 1nF On GATE–, 100mV Step, 5k Pull-Up ● 146 µs

pins are negative. All voltages referenced to ground (GND) unless
specified.

+

Note 3: The absolute voltage difference between FB
force either the GATE

+

or GATE– current to 0µA.

and FB– required to

UW

TYPICAL PERFOR A CE CHARACTERISTICS

Supply Current vs Supply Voltage

4

TA = 25°C

I

CC

3

2

I

EE

SUPPLY CURRENT (mA)

1

0

0

5

10

SUPPLY VOLTAGE (V)

Positive Circuit Breaker Sense
Voltage vs FB+ Voltage

50

VCC = 5V

= –5V

V

EE

+

= 2V

ON

40

–

= –2V

ON

= 25°C

T

A

30

VOLTAGE (mV)

+

20

-SENSE

CC

V

10

0

15

20

4220 G01

–1.5

–0.5 0 0.5

–1.0

FB+ VOLTAGE (V)

1.0 1.5 –1.5

4220 G02

Negative Circuit Breaker Sense
Voltage vs FB– Voltage

60

50

40

VOLTAGE (mV)

–

30

20

SENSEK-SENSE

10

0

–0.5 0 0.5 1.0 1.5

–1.0

–

VOLTAGE (V)

FB

VCC = 5V

= –5V

V

EE

+

= 2V

ON

–

= –2V

ON

= 25°C

T

A

4220 G03

4

4220f

UW

TYPICAL PERFOR A CE CHARACTERISTICS

GATE+ Drive vs V

8

TA = 25°C

) (V)

7

CC

VEE = –5V

– V

+

GATE

6

DRIVE (V

+

GATE

VEE = –2.7V

5

4

CC

3069121518

VCC (V)

4220 G04

GATE– Drive vs V

10

TA = 25°C

9

VCC = 5V

) (V)

EE

8

– V

–

GATE

7

6

DRIVE (V

–

GATE

5

4

EE

VCC = 2.7V

3069121518

VEE (V)

4220 G05

GATE+ Pull-Up Current vs
GATE+ Voltage

16

14

12

10

8

6

PULL-UP CURRENT (µA)

VCC = 5V

+

GATE

= –5V

V

4

EE

+

= V

V

2

0

0

SENSE

V

SENSE

TA = 25°C

CC

–

= V

EE

24

1357
GATE+ VOLTAGE (V

LT4220

6

+

– VCC) (V)

GATE

4220 G06

GATE+ Pull-Down Current vs
GATE+ Voltage

60

50

40

30

20

PULL-DOWN CURRENT (mA)

+

10

GATE

0

0

48

2 6 10 14

GATE

+

VOLTAGE (V)

PWRGD and FAULT VOL vs
Sink Current

900

VCC = 5V

800

= –5V

V

EE

= 25°C

T

A

700

600

500

(mV)

OL

400

V

300

200

100

0

02

4

SINK CURRENT (mA)

VCC = 5V

= –5V

V

EE

+

ON

= 0V

+

= 2V

FB

= 25°C

T

A

12

4220 G07

FAULT

PWRGD

6810

4220 G10

GATE– Pull-Up Current vs
GATE– Voltage

12

10

8

6

4

PULL-UP CURRENT (µA)

–

VCC = 5V

= –5V

V

EE

SENSE
SENSE– = V
TA = 25°C

0

GATE

+

= V

CC
EE

48

2106

–

VOLTAGE (V

GATE

2

0

TIMER Pull-Up Current vs V

75

TA = 25°C

70

65

60

55

TIMER PULL-UP CURRENT (µA)

50

3069121518

VCC (V)

GATE

–

– VEE) (V)

CC

4220 G08

4220 G11

GATE– Pull-Down Current vs
GATE– Voltage

70

VCC = 5V

= –5V

V

EE

–

60

= 0V

ON

–

= –2V

FB

50

T

= 25°C

A

40

30

20

PULL-DOWN CURRENT (mA)

–

10

GATE

0

0

1

GATE

3658

24

–

VOLTAGE (V

ON+, ON– and FB+, FB
Hysteresis vs Temperature

45.0

44.5

44.0

43.5

43.0

42.5

42.0

HYSTERESIS VOLTAGE (mV)

41.5

41.0
–40

–20 0

20 60

TEMPERATURE (°C)

–

– VEE) (V)

GATE

–

40 80

7

4220 G09

4220 G12

4220f

5