LTC4357 - Positive High Voltage Ideal Diode Controller

LTC4357 4357fd Features applications Description Positive High Voltage Ideal Diode Controller The LTC®4357 is a positive high voltage ideal diode cont...

1 downloads 512 Views 756KB Size
LTC4357 Positive High Voltage Ideal Diode Controller Features

Description

Reduces Power Dissipation by Replacing a Power Schottky Diode with an N-Channel MOSFET n 0.5µs Turn-Off Time Limits Peak Fault Current n Wide Operating Voltage Range: 9V to 80V n Smooth Switchover without Oscillation n No Reverse DC Current n Available in 6-Lead (2mm × 3mm) DFN and 8-Lead MSOP Packages

The LTC®4357 is a positive high voltage ideal diode controller that drives an external N-channel MOSFET to replace a Schottky diode. When used in diode-OR and high current diode applications, the LTC4357 reduces power consumption, heat dissipation, voltage loss and PC board area.

n

Applications n n n n n

N + 1 Redundant Power Supplies High Availability Systems AdvancedTCA Systems Telecom Infrastructure Automotive Systems

The LTC4357 easily ORs power sources to increase total system reliability. In diode-OR applications, the LTC4357 controls the forward voltage drop across the MOSFET to ensure smooth current transfer from one path to the other without oscillation. If the power source fails or is shorted, a fast turn-off minimizes reverse current transients. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.

Typical Application 48V, 10A Diode-OR

Power Dissipation vs Load Current 6

FDB3632

VINA 48V IN

GATE LTC4357

OUT VDD

VOUT TO LOAD

GND

DIODE (MBR10100) 4 3 2

FET (FDB3632) 0

IN

GATE LTC4357

POWER SAVED

1

FDB3632

VINB 48V

POWER DISSIPATION (W)

5

OUT

0

2

4 6 CURRENT (A)

8

10 4357 TA01b

VDD

GND 4357 TA01

*SEE FIGURES 2 AND 3 FOR ADDITIONAL OPTIONAL COMPONENTS

4357fd



LTC4357 Absolute Maximum Ratings

(Notes 1, 2)

Supply Voltages IN............................................................. –1V to 100V OUT, VDD............................................... –0.3V to 100V Output Voltage GATE (Note 3)......................... VIN – 0.2V to VIN + 10V

Operating Ambient Temperature Range LTC4357C................................................. 0°C to 70°C LTC4357I.............................................. –40°C to 85°C LTC4357H........................................... –40°C to 125°C LTC4357MP........................................ –55°C to 125°C Storage Temperature Range.................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) MS Package....................................................... 300°C

pin Configuration TOP VIEW

IN 2

TOP VIEW

6 VDD

OUT 1 7 GND

IN NC NC GATE

5 NC 4 GND

GATE 3

1 2 3 4

8 7 6 5

OUT VDD NC GND

MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 125°C, θJA = 163°C/W

DCB PACKAGE 6-LEAD (2mm s 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 90°C/W EXPOSED PAD (PIN 7) PCB GND CONNECTION OPTIONAL

ORDER INFORMATION LEAD FREE FINISH

TAPE AND REEL

PART MARKING*

PACKAGE DESCRIPTION

TEMPERATURE RANGE

LTC4357CMS8#PBF

LTC4357CMS8#TRPBF

LTCXD

8-Lead Plastic MSOP

0°C to 70°C

LTC4357IMS8#PBF

LTC4357IMS8#TRPBF

LTCXD

8-Lead Plastic MSOP

–40°C to 85°C

LTC4357HMS8#PBF

LTC4357HMS8#TRPBF

LTCXD

8-Lead Plastic MSOP

–40°C to 125°C

LTC4357MPMS8#PBF

LTC4357MPMS8#TRPBF

LTFWZ

8-Lead Plastic MSOP

–55°C to 125°C

LEAD BASED FINISH

TAPE AND REEL

PART MARKING*

PACKAGE DESCRIPTION

TEMPERATURE RANGE

LTC4357MPMS8

LTC4357MPMS8#TR

LTFWZ

8-Lead Plastic MSOP

–55°C to 125°C

LEAD FREE FINISH TAPE AND REEL (MINI)

TAPE AND REEL

PART MARKING*

PACKAGE DESCRIPTION

TEMPERATURE RANGE

LTC4357CDCB#TRMPBF

LTC4357CDCB#TRPBF

LCXF

6-Lead (2mm × 3mm) Plastic DFN

0°C to 70°C

LTC4357IDCB#TRMPBF

LTC4357IDCB#TRPBF

LCXF

6-Lead (2mm × 3mm) Plastic DFN

–40°C to 85°C

LTC4357HDCB#TRMPBF

LTC4357HDCB#TRPBF

LCXF

6-Lead (2mm × 3mm) Plastic DFN

–40°C to 125°C

TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ 4357fd



LTC4357 Electrical Characteristics

The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VOUT = VDD, VDD = 9V to 80V unless otherwise noted. SYMBOL

PARAMETER

CONDITIONS

MIN

VDD

Operating Supply Range

l

IDD

Supply Current

l

IIN

IN Pin Current

VIN = VOUT ±1V

l

IOUT

OUT Pin Current

VIN = VOUT ±1V

l

DVGATE

External N-Channel Gate Drive (VGATE – VIN)

VDD, VOUT = 20V to 80V VDD, VOUT = 9V to 20V

l l

IGATE(UP)

External N-Channel Gate Pull-Up Current VGATE = VIN, VIN – VOUT = 0.1V

IGATE(DOWN)

External N-Channel Gate Pull-Down Current in Fault Condition

tOFF

Gate Turn-Off Time

– VIN – VOUT = 55mV |––1V, VGATE – VIN < 1V, CGATE = 0pF

DVSD

Source-Drain Regulation Voltage (VIN – VOUT)

VGATE – VIN = 2.5V

VGATE = VIN + 5V

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.

TYP

MAX

9

80

UNITS V

0.5

1.25

mA

350

500

µA

80

210

µA

10 4.5

12 6

15 15

V V

l

–14

–20

–26

µA

l

1

2

150

l

10

l

A

300

500

ns

25

55

mV

Note 2: All currents into pins are positive, all voltages are referenced to GND unless otherwise specified. Note 3: An internal clamp limits the GATE pin to a minimum of 10V above IN or 100V above GND. Driving this pin to voltages beyond this clamp may damage the device.

Typical Performance Characteristics VDD Current (IDD vs VDD) 800

IN Current (IIN vs VIN) 400

VDD = VOUT = VIN ± 1V

VDD = VOUT = VIN + 1V

OUT Current (IOUT vs VOUT)

150

VDD = VOUT = VIN – 1V

300

600

180

VDD = VOUT = VIN + 1V

400

IOUT (µA)

IIN (µA)

IDD (µA)

120 200

90 60

100

200

VDD = VOUT = VIN – 1V 30

0

0

20

40 VDD (V)

60

80 4357 G01

0

0

20

40 VIN (V)

60

80 4357 G02

0

0

20

40 VOUT (V)

60

80 4357 G03

4357fd



LTC4357 Typical Performance Characteristics 15

$VGATE = 2.5V

0

DVGATE vs GATE Current (DVGATE vs IGATE)

OUT Current (IOUT vs VIN) 125

VIN > 18V

100

VIN = 12V

75

VOUT = 12V, VIN = VDD

IGATE (µA)

$VGATE (V)

10

–25

IOUT (µA)

25

GATE Current vs Forward Drop (IGATE vs DVSD)

VIN = 9V

50

5 25

–50 –50

0

50 VSD (mV)

100

0

150

0

5

10 15 IGATE (µA)

20

4357 G04

500

0

25

0

2

8 6 VIN (V)

4

10

12

14 4357 G06

4357 G05

FET Turn-Off Time vs GATE Capacitance

FET Turn-Off Time vs Initial Overdrive 400

VGATE < VIN + 1V $VSD = 55mV –1V

400

VIN = 48V $VSD = VINITIAL –1V

300

tPD (ns)

tOFF (ns)

300

200

100

100 0

200

0

20

40

60

0

80

0

0.2

0.6 0.4 VINITIAL (V)

CGATE (nF) 4357 G07

FET Load Current vs DVSD 10

VIN = 48V $VSD = 55mV VFINAL

VIN = 48V WITH FET (FDB3632)

8

tPD (ns)

LOAD CURRENT (A)

1500

1000

500

0

1.0 4357 G08

FET Turn-Off Time vs Final Overdrive 2000

0.8

6

4

2

–1

–0.8

–0.4 –0.6 VFINAL (V)

–0.2

0

0

0

50

25 ∆VSD (mV)

75 4357 G10

4357 G09

4357fd



LTC4357 Pin Functions Exposed Pad: Exposed pad may be left open or connected to GND. GATE: Gate Drive Output. The GATE pin pulls high, enhancing the N-channel MOSFET when the load current creates more than 25mV of voltage drop across the MOSFET. When the load current is small, the gate is actively driven to maintain 25mV across the MOSFET. If reverse current develops more than –25mV of voltage drop across the MOSFET, a fast pull-down circuit quickly connects the GATE pin to the IN pin, turning off the MOSFET.

is used to control the source-drain voltage across the MOSFET. The GATE fast pull-down current is returned through the IN pin. Connect this pin as close as possible to the MOSFET source. NC: No Connection. Not internally connected.

GND: Device Ground.

OUT: Drain Voltage Sense. OUT is the cathode of the ideal diode and the common output when multiple LTC4357s are configured as an ideal diode-OR. It connects to the drain of the N-channel MOSFET. The voltage sensed at this pin is used to control the source-drain voltage across the MOSFET.

IN: Input Voltage and GATE Fast Pull-Down Return. IN is the anode of the ideal diode and connects to the source of the N-channel MOSFET. The voltage sensed at this pin

VDD: Positive Supply Input. The LTC4357 is powered from the VDD pin. Connect this pin to OUT either directly or through an RC hold-up circuit.

block diagram IN

OUT

GATE

17V

CHARGE PUMP VDD

+

+

– 25mV

FPD COMP

+ –

GATE AMP

– + –

IN

25mV

GND 4357 BD

4357fd



LTC4357 Operation High availability systems often employ parallel-connected power supplies or battery feeds to achieve redundancy and enhance system reliability. ORing diodes have been a popular means of connecting these supplies at the point of load. The disadvantage of this approach is the forward voltage drop and resulting efficiency loss. This drop reduces the available supply voltage and dissipates significant power. Using an N-channel MOSFET to replace a Schottky diode reduces the power dissipation and eliminates the need for costly heat sinks or large thermal layouts in high power applications. The LTC4357 controls an external N-channel MOSFET to form an ideal diode. The voltage across the source and drain is monitored by the IN and OUT pins, and the GATE pin drives the MOSFET to control its operation. In effect the MOSFET source and drain serve as the anode and cathode of an ideal diode. At power-up, the load current initially flows through the body diode of the MOSFET. The resulting high forward

voltage is detected at the IN and OUT pins, and the LTC4357 drives the GATE pin to servo the forward drop to 25mV. If the load current causes more than 25mV of voltage drop when the MOSFET gate is driven fully on, the forward voltage is equal to RDS(ON) • ILOAD. If the load current is reduced causing the forward drop to fall below 25mV, the MOSFET gate is driven lower by a weak pull-down in an attempt to maintain the drop at 25mV. If the load current reverses and the voltage across IN to OUT is more negative than –25mV the LTC4357 responds by pulling the MOSFET gate low with a strong pull-down. In the event of a power supply failure, such as if the output of a fully loaded supply is suddenly shorted to ground, reverse current temporarily flows through the MOSFET that is on. This current is sourced from any load capacitance and from the other supplies. The LTC4357 quickly responds to this condition turning off the MOSFET in about 500ns, thus minimizing the disturbance to the output bus.

Applications Information MOSFET Selection

ORing Two-Supply Outputs

The LTC4357 drives an N-channel MOSFET to conduct the load current. The important features of the MOSFET are on-resistance, RDS(ON), the maximum drain-source voltage, VDSS, and the gate threshold voltage.

Where LTC4357s are used to combine the outputs of two power supplies, the supply with the highest output voltage sources most or all of the load current. If this supply’s output is quickly shorted to ground while delivering load current, the flow of current temporarily reverses and flows backwards through the LTC4357’s MOSFET. When the reverse current produces a voltage drop across the MOSFET of more than –25mV, the LTC4357’s fast pull-down activates and quickly turns off the MOSFET.

Gate drive is compatible with 4.5V logic-level MOSFETs in low voltage applications (VDD = 9V to 20V). At higher voltages (VDD = 20V to 80V) standard 10V threshold MOSFETs may be used. An internal clamp limits the gate drive to 15V between the GATE and IN pins. An external Zener clamp may be added between GATE and IN for MOSFETs with a VGS(MAX) of less than 15V. The maximum allowable drain-source voltage, BVDSS, must be higher than the power supply voltage. If an input is connected to GND, the full supply voltage will appear across the MOSFET.

If the other, initially lower, supply was not delivering load current at the time of the fault, the output falls until the body diode of its ORing MOSFET conducts. Meanwhile, the LTC4357 charges its MOSFET gate with 20µA until the forward drop is reduced to 25mV. If instead this supply was delivering load current at the time of the fault, its associated ORing MOSFET was already driven at least partially on, and the LTC4357 will simply drive the MOSFET gate harder in an effort to maintain a drop of 25mV. 4357fd



LTC4357 Applications Information Load Sharing

Input Short-Circuit Faults

The application in Figure 1 combines the outputs of multiple, redundant supplies using a simple technique known as droop sharing. Load current is first taken from the highest output, with the low outputs contributing as the output voltage falls under increased loading. The 25mV regulation technique ensures smooth load sharing between outputs without oscillation. The degree of sharing is a function of RDS(ON), the output impedance of the supplies and their initial output voltages.

The dynamic behavior of an active, ideal diode entering reverse bias is most accurately characterized by a delay followed by a period of reverse recovery. During the delay phase some reverse current is built up, limited by parasitic resistances and inductances. During the reverse recovery phase, energy stored in the parasitic inductances is transferred to other elements in the circuit. Current slew rates during reverse recovery may reach 100A/µs or higher.

M1 FDB3632

VINA 48V

48V BUS

PSA RTNA

IN

GATE LTC4357

OUT VDD

GND

M2 FDB3632

VINB 48V PSB RTNB

IN

GATE LTC4357

OUT VDD

GND

M3 FDB3632

VINC 48V PSC RTNC

IN

GATE LTC4357

OUT VDD

GND 4357 F01

Figure 1. Droop Sharing Redundant Supplies

High slew rates coupled with parasitic inductances in series with the input and output paths may cause potentially destructive transients to appear at the IN and OUT pins of the LTC4357 during reverse recovery. A zero impedance short-circuit directly across the input of the circuit is especially troublesome because it permits the highest possible reverse current to build up during the delay phase. When the MOSFET finally commutates the reverse current the LTC4357 IN pin experiences a negative voltage spike, while the OUT pin spikes in the positive direction. To prevent damage to the LTC4357 under conditions of input short-circuit, protect the IN pin and OUT pin as shown in Figure 2. The IN pin is protected by clamping to the GND pin in the negative direction. Protect the OUT pin with a clamp, such as with a TVS or TransZorb, or with a local bypass capacitor of at least 10µF. In low voltage applications the MOSFET's drain-source breakdown may be sufficient to protect the OUT pin, provided BVDSS + VIN < 100V. Parasitic inductance between the load bypass and the LTC4357 allows a zero impedance input short to collapse the voltage at the VDD pin, which increases the total turn-off time (tOFF). For applications up to 30V, bypass the VDD pin with 39µF; above 30V use at least 100µF. If VDD is powered from the output side, one capacitor serves to guard against VDD collapse and also protect OUT from voltage spikes. If the OUT pin is protected by a diode clamp or if VDD is powered from the input side, decouple the VDD pin with a separate 100Ω, 100nF filter (see Figure 3). In applications above 10A increase the filter capacitor to 1µF.

4357fd



LTC4357 Applications Information INPUT PARASITIC INDUCTANCE VIN

+



INPUT SHORT

OUTPUT PARASITIC INDUCTANCE

REVERSE RECOVERY CURRENT

+

M1

IN

DIN SBR1U150SA

GATE

OUT COUT 10µF

VDD

LTC4357

OR



VOUT

DCLAMP SMAT70A

CLOAD

GND 4357 F02

Figure 2. Reverse Recovery Produces Inductive Spikes at the IN and OUT Pin. The Polarity of Step Recovery Spikes is Shown Across Parasitic Inductances OUTPUT PARASITIC INDUCTANCE

M1

VIN

INPUT SHORT

IN

GATE

OUT

LTC4357

VOUT

R1 100Ω COUT

OR

VDD

CLOAD

C1 100nF

GND 4357 F03

Figure 3. Protecting Against Collapse of VDD During Reverse Recovery

Design Example The following design example demonstrates the calculations involved for selecting components in a 12V system with 10A maximum load current (see Figure 4).

M1 Si4874DY

VIN1 12V

IN

First, calculate the RDS(ON) of the MOSFET to achieve the desired forward drop at full load. Assuming VDROP = 0.1V, RDS(ON) ≤

VDROP I LOAD

=

The Si4874DY offers a good solution, in an S8 package with RDS(ON) = 10mΩ(max) and BVDSS of 30V. The maximum power dissipation in the MOSFET is:

LTC4357

P = ILOAD2 • RDS(ON) = (10A)2 • 10mW = 1W

With less than 39µF of local bypass, the recommended RC values of 100W and 0.1µF were used in Figure 4.

OUT

R1 100Ω

VDD C1 0.1µF

GND

0.1V 10A

RDS(ON) ≤ 10mΩ

GATE

VOUT TO LOAD

M2 Si4874DY

VIN2 12V

IN

GATE LTC4357

OUT

R1 100Ω

VDD C1 0.1µF

GND 4357 F04

Figure 4. 12V, 10A Diode-OR

Since BVDSS + VIN is much less than 100V, output clamping is unnecessary. 4357fd



LTC4357 Applications Information Layout Considerations Connect the IN and OUT pins as close as possible to the MOSFET’s source and drain pins. Keep the traces to the MOSFET wide and short to minimize resistive losses. See Figure 5.

VIN

1 S

D 8

2 S

D 7

3 S 4 G

MOSFET

For the DFN package, pin spacing may be a concern at voltages greater than 30V. Check creepage and clearance guidelines to determine if this is an issue. To increase the pin spacing between high voltage and ground pins, leave the exposed pad connection open. Use no-clean solder to minimize PCB contamination.

1 S

D 8

2 S

D 7

D 6

3 S

D 6

D 5

4 G

D 5

OUT

6

4357 F05

7

GATE

1

LTC4357

VOUT

IN GATE

3

OUT

VIN

2

IN

VOUT

5

4

Figure 5. Layout Considerations

4357fd



LTC4357 Typical Applications Solar Panel Charging a Battery M1 FDB3632

14V SHUNT REGULATOR

100W SOLAR PANEL

R1 100Ω

IN

GATE

VDD

OUT

+

LTC4357

C1 0.1µF

12V BATTERY

LOAD

GND 4357 TA02

–12V Reverse Input Protection

–48V Reverse Input Protection

M1 Si4874DY

VIN 12V

CLOAD IN

GATE

VOUT 12V 10A

CLOAD IN

OUT

LTC4357

M1 FDB3632

VIN 48V

GATE LTC4357

VDD

OUT VDD DCLAMP SMAT70A

GND

GND D1 MMBD1205

4357 TA03

D1 MMBD1205

VOUT 48V 10A

4357 TA04

Low Current Shutdown M1 FDS3672

VIN 48V 5A

VOUT DCLAMP SMAT70A

10M R1 100Ω

IN VDD

C1 0.1µF

GATE

OUT

LTC4357 GND 4357 TA05

ON OFF

G1 BSS123

4357fd

10

LTC4357 Package Description DCB Package 6-Lead Plastic DFN (2mm × 3mm)

(Reference LTC DWG # 05-08-1715 Rev A)

R = 0.115 TYP

2.00 p0.10 (2 SIDES)

R = 0.05 TYP

0.70 p0.05

3.55 p0.05

1.65 p0.05 (2 SIDES)

3.00 p0.10 (2 SIDES)

0.40 p 0.10 4

6

1.65 p 0.10 (2 SIDES)

2.15 p0.05 PACKAGE OUTLINE

PIN 1 NOTCH R0.20 OR 0.25 s 45o CHAMFER

PIN 1 BAR TOP MARK (SEE NOTE 6) 3

0.25 p 0.05 0.50 BSC 1.35 p0.05 (2 SIDES)

0.200 REF

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS

0.75 p0.05

1

(DCB6) DFN 0405

0.25 p 0.05 0.50 BSC

1.35 p0.10 (2 SIDES) 0.00 – 0.05

BOTTOM VIEW—EXPOSED PAD

NOTE: 1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (TBD) 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE

4357fd

11

LTC4357 Package Description MS8 Package 8-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1660 Rev F)

3.00 p 0.102 (.118 p .004) (NOTE 3)

0.889 p 0.127 (.035 p .005)

5.23 (.206) MIN

0.254 (.010)

7 6 5

0.52 (.0205) REF

3.00 p 0.102 (.118 p .004) (NOTE 4)

4.90 p 0.152 (.193 p .006)

DETAIL “A” 0o – 6o TYP

GAUGE PLANE

3.20 – 3.45 (.126 – .136)

0.53 p 0.152 (.021 p .006) DETAIL “A”

0.42 p 0.038 (.0165 p .0015) TYP

8

0.65 (.0256) BSC

1 1.10 (.043) MAX

2 3

4 0.86 (.034) REF

0.18 (.007)

RECOMMENDED SOLDER PAD LAYOUT NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

SEATING PLANE

0.22 – 0.38 (.009 – .015) TYP

0.65 (.0256) BSC

0.1016 p 0.0508 (.004 p .002) MSOP (MS8) 0307 REV F

4357fd

12

LTC4357 Revision History

(Revision history begins at Rev D)

REV

DATE

DESCRIPTION

PAGE NUMBER

D

09/10

Revised θJA value for MS8 package in Pin Configuration section and added MP-grade to Order Information section Added two new plots and revised remaining curves in Typical Performance Characteristics section

2 3, 4

Updated Electrical Characteristics section

4

Revised Figure 2 and Figure 4 in Applications Information section

8

4357fd

Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

13

LTC4357 Typical Application Plug-In Card Input Diode for Supply Hold-Up BACKPLANE PLUG-IN CARD CONNECTORS CONNECTOR 1

FDB3632

48V

IN

GATE LTC4357

Hot Swap CONTROLLER

VOUT1

OUT

+

VDD

CHOLDUP

SMAT70A

GND

GND FDB3632

IN

GATE LTC4357

Hot Swap CONTROLLER

VOUT2

OUT

+

VDD

CHOLDUP

SMAT70A

GND

GND GND

PLUG-IN CARD CONNECTOR 2

4357 TA06

Related Parts PART NUMBER

DESCRIPTION

COMMENTS

LT1641-1/LT1641-2

Positive High Voltage Hot Swap Controllers

Active Current Limiting, Supplies from 9V to 80V

LTC1921

Dual –48V Supply and Fuse Monitor

UV/OV Monitor, –10V to –80V Operation, MSOP Package

LT4250

–48V Hot Swap Controller

Active Current Limiting, Supplies from –18V to –80V

LTC4251/LTC4251-1/ LTC4251-2

–48V Hot Swap Controllers in SOT-23

Fast Active Current Limiting, Supplies from –15V

LTC4252-1/LTC4252-2/ LTC4252-1A/LTC4252-2A

–48V Hot Swap Controllers in MS8/MS10

Fast Active Current Limiting, Supplies from –15V, Drain Accelerated Response

LTC4253

–48V Hot Swap Controller with Sequencer

Fast Active Current Limiting, Supplies from –15V, Drain Accelerated Response, Sequenced Power Good Outputs

LT4256

Positive 48V Hot Swap Controller with Open-Circuit Detect

Foldback Current Limiting, Open-Circuit and Overcurrent Fault Output, Up to 80V Supply

LTC4260

Positive High Voltage Hot Swap Controller

With I2C and ADC, Supplies from 8.5V to 80V

LTC4261

Negative High Voltage Hot Swap Controller

With I2C and 10-Bit ADC, Adjustable Inrush and Overcurrent Limits

LTC4352

Ideal Diode Controller with Monitor

Controls N-Channel MOSFET, 0V to 18V Operation

LTC4354

Negative Voltage Diode-OR Controller and Monitor

Controls Two N-Channel MOSFETs, 1µs Turn-Off, 80V Operation

LTC4355

Positive Voltage Diode-OR Controller and Monitor

Controls Two N-Channel MOSFETs, 0.5µs Turn-Off, 80V Operation

LT4356-1/LT4356-2/ LT4356-3

Surge Stopper, Overvoltage and Overcurrent Protection Regulator

Wide Operation Range: 4V to 80V, Reverse Input Protection to –60V, Adjustable Output Clamp Voltage

4357fd

14 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 l FAX: (408) 434-0507

l

www.linear.com

LT 0910 REV D • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 2007