LINEAR TECHNOLOGY LTC4217 Technical data

LTC4217

2A Integrated Hot Swap

Controller

FEATURES

n

Small Footprint

n

25mΩ MOSFET and 7.5mΩ R

n

Wide Operating Voltage Range: 2.9V to 26.5V

n

Adjustable, 5% Accurate Current Limit

n

Current and Temperature Monitor Outputs

n

Overtemperature Protection

n

Adjustable Current Limit Timer Before Fault

n

Powergood and Fault Outputs

n

Adjustable Inrush Current Control

n

2% Accurate Undervoltage and Overvoltage

SENSE

Protection

n

Available in 20-Lead TSSOP and 16-Lead

5mm × 3mm DFN Packages

APPLICATIONS

n

RAID Systems

n

Server I/O Cards

n

Industrial

DESCRIPTION

The LTC®4217 is an integrated solution for Hot Swap™
applications that allows a board to be safely inserted and
removed from a live backplane. The part integrates a Hot
Swap controller, power MOSFET and current sense resistor
in a single package for small form factor applications. A
dedicated 12V version (LTC4217-12) contains preset 12V
specifi c thresholds, while the standard LTC4217 allows
adjustable thresholds.

The LTC4217 provides separate inrush current control
and an accurate (5%) 2A current limit with current fold­back limiting. The current limit threshold can be adjusted
dynamically using an external pin. Additional features
include a current monitor output that amplifi es the sense
resistor voltage for ground referenced current sensing
and a MOSFET temperature monitor output. Thermal limit,
overvoltage, undervoltage and powergood monitoring are
also provided.

L, LT, LTC and LTM 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 APPLICATION

12V, 1.5A Card Resident Application

12V

AUTO

RETRY

0.1μF

V

DD

UV

LTC4217DHC-12

FLT

TIMER

INTV

CC

GND

OUT

I

MON

PG

12V

10k

20k

Power-Up Waveforms

V

OUT

330μF

ADC

12V

1.5A

4217 TA01a

V

10V/DIV

0.1A/DIV

V

OUT

10V/DIV

10V/DIV

IN

I

IN

P

G

25ms/DIV

4217 TA01b

4217fb

+

1

LTC4217

(

ABSOLUTE MAXIMUM RATINGS

(Notes 1, 2)

Supply Voltage (VDD) ................................. –0.3V to 28V

Input Voltages

FB, OV, UV .............................................. –0.3V to 12V

TIMER ................................................... –0.3V to 3.5V

SENSE .............................V

– 10V or – 0.3V to V

DD

DD

Output Voltages

, I

I

SET

................................................. –0.3V to 3V

MON

PG, FLT .................................................. –0.3V to 35V

OUT ............................................–0.3V to V

INTV

.................................................. –0.3V to 3.5V

CC

+ 0.3V

DD

PACKAGE/ORDER INFORMATION

TOP VIEW

1

V

DD

2

UV

3

OV

4

TIMER

5

INTV

CC

6

GND

7

OUT

8

OUT

DHC PACKAGE

5mm s 3mm) PLASTIC DFN

16-LEAD

T

= 125°C, θJA = 43°C/W

JMAX

EXPOSED PAD (PIN 17) IS SENSE,

= 43°C/W SOLDERED, OTHERWISE θJA = 140°C/W

θ

JA

16

V

DD

15

I

SET

14

I

MON

13

17

FB

12

FLT

11

PG

10

GATE

9

OUT

GATE (Note 3) ........................................ –0.3V to 33V

Operating Temperature Range

LTC4217C ................................................ 0°C to 70°C

LTC4217I..............................................–40°C to 85°C

Junction Temperature (Notes 4, 5)........................ 125°C

Storage Temperature Range

DHC Package ..................................... –65°C to 125°C

FE Package ........................................–65°C to 150°C

Lead Temperature (Soldering, 10 sec)

FE Package Only ...............................................300°C

TOP VIEW

1

SENSE

2

V

DD

3

UV

4

OV

5

TIMER

INTV

CC

GND

OUT

OUT

SENSE

20-LEAD PLASTIC TSSOP

T

JMAX

EXPOSED PAD (PIN 21) IS SENSE,

= 38°C/W SOLDERED, OTHERWISE θJA = 130°C/W

θ

JA

21

6

7

8

9

10

FE PACKAGE

= 125°C, θJA = 38°C/W

SENSE

20

V

19

DD

I

18

SET

I

17

MON

FB

16

FLT

15

PG

14

GATE

13

OUT

12

SENSE

11

4217fb

2

LTC4217

ORDER INFORMATION

LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE

LTC4217CDHC-12#PBF LTC4217CDHC-12#TRPBF 421712

LTC4217IDHC-12#PBF LTC4217IDHC-12#TRPBF 421712

LTC4217CDHC#PBF LTC4217CDHC#TRPBF 4217

LTC4217IDHC#PBF LTC4217IDHC#TRPBF 4217

16-Lead (5mm × 3mm) Plastic DFN
16-Lead (5mm × 3mm) Plastic DFN
16-Lead (5mm × 3mm) Plastic DFN
16-Lead (5mm × 3mm) Plastic DFN

LTC4217CFE#PBF LTC4217CFE#TRPBF LTC4217FE 20-Lead Plastic TSSOP 0°C to 70°C
LTC4217IFE#PBF LTC4217IFE#TRPBF LTC4217FE 20-Lead Plastic TSSOP –40°C to 85°C

LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE

LTC4217CDHC-12 LTC4217CDHC-12#TR 421712

LTC4217IDHC-12 LTC4217IDHC-12#TR 421712

LTC4217CDHC LTC4217CDHC#TR 4217

LTC4217IDHC LTC4217IDHC#TR 4217

16-Lead (5mm × 3mm) Plastic DFN
16-Lead (5mm × 3mm) Plastic DFN
16-Lead (5mm × 3mm) Plastic DFN
16-Lead (5mm × 3mm) Plastic DFN

LTC4217CFE LTC4217CFE#TR LTC4217FE 20-Lead Plastic TSSOP 0°C to 70°C
LTC4217IFE LTC4217IFE#TR LTC4217FE 20-Lead Plastic TSSOP –40°C to 85°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
For more information on lead free part marking, go to:

For more information on tape and reel specifi cations, go to:

http://www.linear.com/leadfree/

http://www.linear.com/tapeandreel/

0°C to 70°C

–40°C to 85°C

0°C to 70°C

–40°C to 85°C

0°C to 70°C

–40°C to 85°C

0°C to 70°C

–40°C to 85°C

ELECTRICAL CHARACTERISTICS

The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at TA = 25°C. VDD = 12V unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

DC Characteristics

V

DD

I

DD

V

DD(UVL)

V

DD(UVTH)

ΔV

DD(UVHYST)

V

DD(OVTH)

ΔV

DD(OVHYST)

V

OUT(PGTH)

ΔV

OUT(PGHYST)

I

OUT

ΔV

/Δt GATE Pin Turn-On Ramp Rate

GATE

R

ON

I

LIM(TH)

Input Supply Range

Input Supply Current MOSFET On, No Load

Input Supply Undervoltage Lockout VDD Rising

Input Supply Undervoltage Threshold LTC4217-12 Only, VDD Rising

Input Supply Undervoltage Hysteresis LTC4217-12 Only

Input Supply Overvoltage Threshold LTC4217-12 Only, VDD Rising

Input Supply Overvoltage Hysteresis LTC4217-12 Only

Output Powergood Threshold LTC4217-12 Only, V

Output Powergood Hysteresis LTC4217-12 Only

OUT Pin Leakage Current V

MOSFET + Sense Resistor On Resistance Note 6

Current Limit Threshold VFB = 1.23V 1.9 2 2.1 A

= V

OUT

V

= V

OUT

V

= V

OUT

= 1.23V

V

FB

VFB = 0V

= 1.23V, R

V

FB

Rising

OUT

= 0V, VDD = 26.5V

GATE

= 12V, LTC4217 Only

GATE

= 12V, LTC4217-12 Only

GATE

= 20kΩ

SET

l

2.9 26.5 V

l

l

2.65 2.73 2.85 V

l

9.6 9.88 10.2 V

l

520 640 760 mV

l

14.7 15.05 15.4 V

l

183 244 305 mV

l

10.2 10.5 10.8 V

l

127 170 213 mV

l
l

1

l

50

l

0.15 0.3 0.55 V/ms

l

15 32 50

l

1.85 2 2.15 A

l

0.35 0.5 0.7 A

l

0.85 1 1.17 A

1.6 3 mA

0

±150

2

70

90

4

mΩ

μA
μA
μA

4217fb

3

LTC4217

ELECTRICAL CHARACTERISTICS

The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

Inputs

I

IN

R

IN

V

TH

ΔV

OV(HYST)

ΔV

UV(HYST)

V

UV(RTH)

ΔV

FB(HYST)

R

ISET

Outputs

V

OL

I

OH

V

TIMER(H)

V

TIMER(L)

I

TIMER(UP)

I

TIMER(DN)

I

TIMER(RATIO)

A

IMON

I

OFF(IMON)

I

GATE(UP)

I

GATE(DN)

I

GATE(FST)

AC Characteristics

t

PHL(GATE)

t

PHL(ILIM)

t

D(ON)

t

D(CB)

t

D(AUTO-RETRY)

OV, UV, FB Pin Input Current VIN = 1.2V, LTC4217 Only

OV, UV, FB Pin Input Resistance LTC4217-12 Only

OV, UV, FB Pin Threshold Voltage VIN Rising

OV Pin Hysteresis

UV Pin Hysteresis

UV Pin Reset Threshold Voltage VUV Falling

FB Pin Power Good Hysteresis

I

Pin Output Resistor

SET

PG, FLT Pin Output Low Voltage I
PG, FLT Pin Input Leakage Current V

TIMER Pin High Threshold V

TIMER Pin Low Threshold V

TIMER Pin Pull-Up Current V

TIMER Pin Pull-Down Current V

TIMER Pin Current Ratio I

I

Pin Current Gain I

MON

I

Pin Offset Current I

MON

TIMER(DN)/ITIMER(UP)

Gate Pull-Up Current Gate Drive On, V

Gate Pull-Down Current Gate Drive Off, V

Gate Fast Pull-Down Current Fast Turn Off, V

Input High (OV), Input Low (UV) to Gate Low
Propagation Delay

Short Circuit to Gate Low VFB = 0, Step I

Turn-On Delay Step VUV to 2V, V

Circuit Breaker Filter Delay Time (Internal) VFB = 0V, Step I

Auto-Retry Turn-On Delay (Internal)

= 25°C. VDD = 12V unless otherwise noted.

A

= 2mA

OUT

= 30V

OUT

Rising

TIMER

Falling

TIMER

= 0V

TIMER

= 1.2V

TIMER

= 2A

OUT

= 132mA

OUT

V

< 16.5V Falling

GATE

V

< 16.5V Falling

GATE

GATE

GATE

GATE

SENSE

GATE

SENSE

= V

= 18V, V

= 18V, V

to 1.2A,

> 13V

to 1.2A

= 12V

SOURCE

= 12V

OUT

= 12V 140 mA

OUT

l

l

13 18 23

l

1.21 1.235 1.26 V

l

10 20 30 mV

l

50 80 110 mV

l

0.55 0.62 0.7 V

l

10 20 30 mV

l

19.5 20 20.5

l

l

l

1.2 1.235 1.28 V

l

0.1 0.21 0.3 V

l

–80 –100 –120 μA

l

1.4 2 2.6 μA

l

1.6 2 2.7 %

l

47.5 50 52.5 μA/A

l

l

–19 –24 –29 μA

l

190 250 340 μA

l

l

l

50 100 150 ms

l

1.5 2 2.7 ms

l

50 100 150 ms

0±1 μA

0.4 0.8 V

0 ±10 μA

0 ±7.5 μA

810 μs

15 μs

kΩ

kΩ

Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.

Note 2: All currents into pins are positive, all voltages are referenced to
GND unless otherwise specifi ed.

Note 3: An internal clamp limits the GATE pin to a maximum of 6.5V
above OUT. Driving this pin to voltages beyond the clamp may damage the
device.

Note 4: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specifi ed maximum operating junction
temperature may impair device reliability.

4

Note 5: T
dissipation, P

LTC4217DHC, LTC4217DHC-12: T
LTC4217FE: T

is calculated from the ambient temperature, TA, and power

J

, according to the formula:

D

= TA + (PD • 43°C/W)

J

= TA + (PD • 38°C/W)

J

Note 6: Switch on-resistance is guaranteed by design and test correlation
on the DHC package.

4217fb

LTC4217

TYPICAL PERFORMANCE CHARACTERISTICS

2.0

1.8

1.6

(mA)

DD

I

1.4

1.2

1.0

IDD vs V

0

DD

85°C

25°C

–40°C

5 101520

VDD (V)

UV Hysteresis vs Temperature

0.10

25 30

4217 G01

INTVCC Load Regulation

3.5

3.0

2.5

2.0

(V)

CC

1.5

INTV

1.0

0.5

0

0

I

LOAD

Timer Pull-Up Current vs
Temperature

–110

VDD = 3.3V

(mA)

T

= 25°C, VDD = 12V unless otherwise noted.

A

UV Low-High Threshold vs
Temperature

1.234

VDD = 5V

1.232

1.230

1.228

UV LOW-HIGH HRESHOLD (V)

1.226
–50

–14–12–10–8–6–4–2

4217 G02

–25 0 25

TEMPERATURE (°C)

Current Limit Delay

vs Overdrive)

1000

(t

PHL(ILIM)

50 75 100

4217 G03

0.08

0.06

UV HYSTERESIS (V)

0.04
–25 0 25

–50

TEMPERATURE (°C)

Current Limit Threshold Foldback

2.5

2.0

1.5

1.0

CURRENT LIMIT VALUE (A)

0.5

0

0.2 0.4 0.6 0.8

0

FB VOLTAGE (V)

50 75 100

4217 G04

1.0 1.2

4217 G07

–105

–100

–95

TIMER PULL-UP CURRENT (μA)

–90

–50

–25 0 25

TEMPERATURE (°C)

Current Limit Adjustment
(I

CURRENT LIMIT THRESHOLD VALUE (A)

2.5

2.0

1.5

1.0

0.5

vs R

OUT

0

1k

)I

SET

10k 100k 1M

R

SET

50 75 100

(Ω)

4217 G05

4217 G08

10M

100

10

1

CURRENT LIMIT PROPAGATION DELAY (μs)

0.1

22

21

20

RESISTOR (kΩ)

SET

I

19

18

2468

010

SET

–50

OUTPUT CURRENT (A)

Resistor vs Temperature

–25 0 25

TEMPERATURE (°C)

50 75 100

4217 G06

4217 G09

4217fb

5