LINEAR TECHNOLOGY LTC4241 Technical data

FEATURES

■

Allows Safe Board Insertion and Removal from a Live PCI Slot

■

Controls 3.3V, 5V, –12V, 12V and 3.3V Auxiliary Supplies

■

Independent 3.3V Auxiliary Supply Hot Swap Controller

■

Adjustable Foldback Current Limit with Circuit Breaker

■

Adjustable Supply Voltage Power-Up Rate

■

High Side Drive for External N-Channel FETs

■

–12V and 12V On-Chip Switches

■

Fault and Power Good Outputs

U

APPLICATIO S

■

PCI-Based Servers

■

Computer Systems

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

Hot Swap is a trademark of Linear Technology Corporation.

TM

LTC4241

PCI-Bus with 3.3V Auxiliary

Hot Swap Controller

U

DESCRIPTIO

The LTC®4241 is a Hot Swap controller that allows a board to be safely inserted and removed from a live PCI-bus slot. It has a primary controller that controls the four PCI supplies and an independent auxiliary controller to control the 3.3V auxiliary supply. External N-channel transistors are used to control the 3.3V, 5V and 3.3V auxiliary supplies while on-chip switches control the –12V and 12V supplies. The 3.3V, 5V and 3.3V auxiliary supplies can be ramped up at an adjustable rate. Electronic circuit breakers protect all five supplies against overcurrent faults. The foldback current limit feature reduces current spikes and power dissipation when shorts occur. The PWRGD output of the primary controller indicates when all four PCI supplies are within tolerance. The FAULT output indicates an overcurrent condition for any of the five supplies.

The LTC4241 is available in the 20-pin narrow SSOP package.

TYPICAL APPLICATIO

SYSTEM

POWER

SUPPLY

R8 10k

PCI

POWER

SYSTEM

CONTROLLER

RESET

R9 10k

U

R1

0.007Ω

R2

0.005Ω

R3

0.07Ω

11 10 9 13 14 15 3 17 16 18

AUXIN AUXSENSE AUXGATE 3VIN3V

8

GND

1

12V

IN

2

V

EEIN

12

AUXON

5

ON

6

FAULT

7

PWRGD

Si2306DS

C3

10nF

Q3

R6 10Ω

SENSE

LTC4241

Q2

IRF7413

R5 10Ω

GATE 3V

OUT5VIN5VSENSE5VOUT

Q1

IRF7413

12V

OUT

V

EEOUT

TIMER

R4 10Ω

GND

5V 5A

3.3V

7.6A

3.3V

AUX

500mA

R7 100Ω

C1

0.047µF

12V

20

500mA

–12V

19

100mA

4

C2

0.1µF

BACKPLANE CONNECTOR

LOGIC

RESET

4241 F01

Figure 1. Hot Swappable PCI and 3.3V Auxiliary Supplies

sn4241 4241f

1

LTC4241

WW

W

U

ABSOLUTE AXI U RATI GS

(Note 1)

Supply Voltages

12VIN................................................................... 14V

V

.................................................................. –14V

EEIN

AUXIN ................................................................... 7V

Input Voltage

ON .........................................................–0.3V to 14V

AUXON ..................................................–0.3V to 14V

Output Voltages

(FAULT, PWRGD) ..................................–0.3V to 14V

Analog Voltages

TIMER, 3VIN, 3V 5V 3V

SENSE

, 5V

OUT

, 5V

.............................

IN

........................................–0.3V to 14V

OUT

AUXSENSE ..........................–0.3V to (AUXIN + 0.3V)

V 12V

................................................ –14V to + 0.3V

EEOUT

..................................................–0.3V to 14V

OUT

AUXGATE ......................... Internally Limited (Note 3)

Operating Temperature Range

LTC4241CGN........................................... 0°C to 70°C

LTC4241IGN........................................–40°C to 85°C

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

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

SENSE

, GATE,

–0.3V to (12VIN + 0.3V)

UUW

PACKAGE/ORDER I FOR ATIO

ORDER PART

NUMBER

TOP VIEW

1

12V

IN

2

V

EEIN

3

3V

OUT

4

TIMER

5

ON

6

FAULT

PWRGD

AUXGATE

AUXSENSE

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

7 8

GND

9

10

GN PACKAGE

20-LEAD NARROW PLASTIC SSOP

T

= 150°C, θJA = 135°C/W

JMAX

12V

20

OUT

V

19

EEOUT

5V

18

OUT

5V

17

IN

5V

16

SENSE

GATE

15

3V

14

SENSE

3V

13

IN

AUXON

12

AUXIN

11

LTC4241CGN LTC4241IGN

DC ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at TA = 25°C. V V

= 3.3V. (Note 2)

AUXIN

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

I

DD

V

LKO

V

LKH

V

SENSE5(TH)

V

SENSE3(TH)

t

CB

I

GATE

V

Supply Current ON = V

12VIN

V

Supply Current AUXON = V

AUXIN

Undervoltage Lockout, 12V Low-to-High Transition 3V

Undervoltage Lockout Hysteresis 3VIN, 5V

Current Limit Sense Voltage V Threshold (V

Circuit Breaker Trip Filter Time (V

GATE Pin Output Current ON High, FAULT High, V

5VIN

3VIN

– V

)V

5VSENSE

)V

3VSENSE

12VIN

IN

5V

IN

AUXIN

IN

AUXIN 120 mV

= 0V ● 5.5 9 14.5 mV

5VOUT

> 4V ● 40 55 70 mV

5VOUT

= 0V ● 5.5 9 14.5 mV

3VOUT

> 2V ● 40 55 70 mV

3VOUT

– V

5VIN

(V

– V

AUXIN

ON Low, FAULT High, V ON High, FAULT Low, V

The ● denotes the specifications which apply over the full operating

= 12V, V

12VIN

AUXIN

) = Step 0 to 100mV 17 µs

5VSENSE

AUXSENSE

) = Step 0 to 100mV 8 µs

= GND ● –20 –60 –100 µA

GATE

= 5V 200 µA

GATE

= 5V 5 25 35 mA

GATE

VEEIN

= –12V, V

= 3.3V, V

3VIN

= 5V,

5VIN

● 2.5 8 mA

● 0.5 1.5 mA

● 6.5 9 10.8 V

● 2.25 2.50 2.75 V

● 3.65 3.90 4.15 V

● 2.35 2.60 2.85 V

20 mV

sn4241 4241f

2

LTC4241

DC ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at TA = 25°C. V V

= 3.3V. (Note 2)

AUXIN

The ● denotes the specifications which apply over the full operating

12VIN

= 12V, V

VEEIN

= –12V, V

= 3.3V, V

3VIN

5VIN

= 5V,

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

∆V

GATE

V

DROP

I

CL(12)

I

CL(VEE)

T

TS

V

PG(TH)

V

PGH

V

IL

V

IH

V

OL

I

IN

External Gate Voltage (V Internal Switch Voltage Drop (V

Current Limit 12VIN = 12V, 12V

Current Limit V

(V

12V

EEIN

V

EEIN

12VIN

12VIN EEOUT

– V

GATE

– V

12VOUT

– V

= 12V, 12V

IN

= –12V, V = –12V, V

) ● 100 200 mV

VEEIN

), I

OUT

EEOUT EEOUT

= 500mA ● 200 600 mV

12VOUT

= 100mA ● 120 250 mV

VEEIN

= 0V, TIMER = GND ● –50 –300 –575 mA

= 11V, TIMER = GND ● –525 –850 –1500 mA

= 0V, TIMER = GND ● 50 200 425 mA = –11V, TIMER = GND ● 250 450 750 mA

Thermal Shutdown Temperature 150 °C Power Good Threshold Voltage V

Power Good Hysteresis 3V

Rising ● 10.8 11.1 11.4 V

12VOUT

V

Falling ● –10.2 –10.5 –10.8 V

VEEOUT

Rising ● 2.8 2.9 3.0 V

V

3VOUT

Rising ● 4.5 4.65 4.78 V

V

5VOUT

5V 12V

OUT OUT

OUT

, V

EEOUT

20 mV 30 mV 50 mV

Input Low Voltage ON, AUXON ● 0.8 V Input High Voltage ON, AUXON ● 2V Output Low Voltage FAULT, PWRGD , IOL = 3mA ● 0.4 V AUXON Pin Input Current AUXON = GND ● ±0.08 ±10 µA

AUXON = V

AUXIN

● ±0.08 ±10 µA

ON Pin Input Current ON = GND ● ±0.08 ±10 µA

● ±0.08 ±10 µA

5V

Input Current 5V

SENSE

3V

Input Current 3V

SENSE

ON = V

12VIN

= 5V ● 50 100 µA

SENSE

= 3V ● 50 100 µA

SENSE

5VIN Input Current 5VIN = 5V ● 580 900 µA 3VIN Input Current 3VIN = 3V ● 310 550 µA 5V

R

DIS

I

TIMER

V

TIMER

V

AUXCB

I

AUXGATE

∆V

AUXGATE

Input Current 5V

OUT

3V

Input Current 3V

OUT

5V

Discharge Impedance ON = GND 60 Ω

OUT

3V

Discharge Impedance ON = GND 50 Ω

OUT

Discharge Impedance ON = GND 450 Ω

12V

OUT

Discharge Impedance ON = GND 1600 Ω

V

EEOUT

TIMER Pin Current Timer On, V

TIMER Threshold Voltage (V

12VIN

– V

) ● 0.5 0.9 1.3 V

TIMER

Circuit Breaker Trip Voltage (V

AUXIN

– V

AUXSENSE

) ● 40 50 60 mV

AUXGATE Gate Output Current AUXON High, FAULT High, V

External AUXGATE Gate Voltage (V

= 5V, ON = V

OUT

= 3V, ON = V

OUT

Timer Off, V

12VIN

= GND, ● –15 –22 –27 µA

TIMER

= 5V, 45 mA

TIMER

AUXON Low, FAULT High, V AUXON High, FAULT Low, V

AUXGATE

– V

AUXIN

), V

AUXIN

● 260 500 µA

● 150 350 µA

= GND ● –6 –10 –14 µA

AUXGATE

= 5V 200 µA

AUXGATE

= 10V 50 mA

AUXGATE

= 3.3V ● 5811 V

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 AUXGATE pin clamps the charge pump voltage to a typical maximum operating voltage of 12V. External overdrive of the AUXGATE pin beyond the internal zener voltage may damage the device.

sn4241 4241f

3

LTC4241

TEMPERATURE (°C)

–75 –50 –25

CURRENT LIMIT (mA)

25 500

1200

1000

800

600

400

200

0

4241 • G06

125 15075 100

12V

OUT

= 11V

12V

OUT

= 0V

UW

TYPICAL PERFOR A CE CHARACTERISTICS

3.3V and 5V Current Foldback Profile

12

3V

OUT

10

8

6

4

OUTPUT CURRENT (A)

3VIN = 3.3V

2

0

= 5V

5V

IN

R

= 0.005Ω

SENSE

0.5 OUTPUT VOLTAGE (V)

5V

OUT

2.51.5 3.5 4.5

5.5

4241 • G01

12V Current Foldback Profile

1100

12VIN = 12V

1000

900 800 700 600 500 400 300

OUTPUT CURRENT (mA)

200 100

0

0 1 2 3 4 5 6 7 8 9 10 11 12

OUTPUT VOLTAGE (V)

4241 • G02

–12V Current Foldback Profile

1100

V

= –12V

EEIN

1000

900 800 700 600 500 400 300

OUTPUT CURRENT (mA)

200 100

0

0 –1 –2 –3 –4 –5 –6 –7 –8 –9 –10 –11–12

OUTPUT VOLTAGE (V)

4241 • G03

70

60

50

40

30

20

CURRENT LIMIT VOLTAGE (mV)

10

600

500

400

300

200

CURRENT LIMIT (mA)

100

5VIN Current Limit Voltage vs Temperature

5V

= 5V

OUT

5V

= 0V

OUT

0

–75 –50 –25

V

Current Limit

EEIN

25 500

TEMPERATURE (°C)

vs Temperature

V

= –11V

EEOUT

V

= 0V

EEOUT

0

–75 –50 –25

25 500

TEMPERATURE (°C)

125 15075 100

4241 • G04

125 15075 100

4241 • G07

3VIN Current Limit Voltage vs Temperature

70

60

50

40

30

20

CURRENT LIMIT VOLTAGE (mV)

10

0

–75 –50 –25

(V

AUXIN

3V

TEMPERATURE (°C)

– V

AUXSENSE

OUT

25 500

= 3.3V

= 0V

) Circuit Breaker Trip Voltage vs Temperature

55 54 53 52 51 50 49 48 47 46

CIRCUIT BREAKER TRIP VOLTAGE (mV)

45

–75 –50 –25

25 500

TEMPERATURE (°C)

125 15075 100

4241 • G05

125 15075 100

4241 • G08

12VIN Current Limit vs Temperature

GATE, AUXGATE Output Source Current vs Temperature

90

80

70

60

50

40

30

20

GATE OUTPUT SOURCE CURRENT (µA)

10

–75 –50 –25

GATE

AUXGATE

25 500

TEMPERATURE (°C)

125 15075 100

4241 • G09

sn4241 4241f

12.5

12.0

11.5

11.0

10.5

10.0

9.5

9.0

8.5

AUXGATE OUTPUT SOURCE CURRENT (µA)

4

UW

TYPICAL PERFOR A CE CHARACTERISTICS

LTC4241

GATE, AUXGATE Output Sink Current vs Temperature

350

300

250

200

150

OUTPUT SINK CURRENT (µA)

100

50

–75 –50 –25

TEMPERATURE (°C)

GATE

AUXGATE

25 500

AUXGATE Voltage vs Temperature

11.75

11.60

11.45

11.30

11.15

11.00

AUXGATE VOLTAGE (V)

10.85

10.70 –75 –50 –25

25 500

TEMPERATURE (°C)

125 15075 100

4241 • G10

125 15075 100

4241 • G13

GATE, AUXGATE Fast Pull-Down Current vs Temperature

80

70

60

50

40

30

20

FAST PULL-DOWN CURRENT (mA)

10

0

–75 –50 –25

GATE

TEMPERATURE (°C)

AUXGATE

25 500

12V Internal Switch Voltage Drop vs Temperature

325

I

= 500mA

12VOUT

300

275

250

225

200

175

150

125

INTERNAL SWITCH VOLTAGE DROP (mV)

100

–75 –50 –25

25 500

TEMPERATURE (°C)

125 15075 100

4241 • G11

125 15075 100

4241 • G14

(V

AUXGATE

– V

AUXIN

)

vs Temperature

8.20 AUXIN = 3.3V

8.15

8.10

) (V)

8.05

AUXIN

8.00

– V

7.95

7.90

AUXGATE

(V

7.85

7.80

7.75

–75 –50 –25

25 500

TEMPERATURE (°C)

VEE Internal Switch Voltage Drop vs Temperature

200

I

= 100mA

VEEIN

180

160

140

120

100

80

60

INTERNAL SWITCH VOLTAGE DROP (mV)

40

–75 –50 –25

25 500

TEMPERATURE (°C)

125 15075 100

4241 • G12

125 15075 100

4241 • G15

Power Good Threshold Voltage vs Temperature (12V

11.20

11.15

11.10

11.05

11.00

10.95

POWER GOOD THRESHOLD VOLTAGE (V)

10.90 –75 –50 –25

TEMPERATURE (°C)

OUT

25 500

Power Good Threshold Voltage

)

125 15075 100

4241 • G16

vs Temperature (5V

4.68

4.67

4.66

4.65

4.64

4.63

4.62

4.61

POWER GOOD THRESHOLD VOLTAGE (V)

4.60 –75 –50 –25

TEMPERATURE (°C)

OUT

25 500

)

125 15075 100

4241 • G17

Power Good Threshold Voltage vs Temperature (3V

2.915

2.910

2.905

2.900

2.895

2.890

2.885

2.880

POWER GOOD THRESHOLD VOLTAGE (V)

2.875 –75 –50 –25

TEMPERATURE (°C)

OUT

25 500

)

125 15075 100

4241 • G18

sn4241 4241f

5

LINEAR TECHNOLOGY LTC4241 Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual