LTC4238

1

Rev. 0

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TYPICAL APPLICATION

FEATURES

DESCRIPTION

High Voltage High Current

Hot Swap Controller

The LTC®4238 is a high voltage high current Hot Swap

controller that allows a board to be safely inserted and

removed from a live backplane. Dual 12V gate drive is

well suited for high power applications to either share

safe operating area across parallel MOSFETs or support

a 2-stage start-up that first charges the load capacitance

followed by enabling a low on-resistance path to the load.

The device features active current limiting (ACL) with two

profile limits the power dissipation to be no higher than

a fixed value, while the high power profile allows the part

to ride through large input steps during operation.

The LTC4238 notifies when output power is good. In

addition, it has protection features that respond to input

undervoltage, overvoltage; and generate a fault when

there is an overcurrent or FET bad condition.

48V, 63A Hot Swap Controller in Low Stress Staged Start Mode

APPLICATIONS

n

Allows Safe Board Insertion into Live Backplane

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Wide Operating Voltage Range: 6.5V to 80V

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Drives Two Gates for High Power Applications

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Configurable Parallel, Staged Start or

Single MOSFET Modes

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Adjustable Precision Current Limit: 6mV to 20mV

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Current Foldback Limits MOSFET Power

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SOA Timer Optimizes MOSFET Capability

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n

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Parallelable Controllers for Very High Current Levels

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Available in 24-Lead Narrow SSOP and 24-Pin

4mm × 5mm QFN Packages

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Live Board Insertion in 12V, 24V and 48V Systems

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Industrial High Side Switch/Circuit Breaker

n

Computers, Servers

n

Vehicle Electrical Systems

All registered trademarks and trademarks are the property of their respective owners. Protected

by U.S. patents, including 9634480, 9634481, 9671465B2, 10003190B2. More patents pending.

Start-Up Behavior

0.2m

4m

BYPASS FET

10

START-UP FET

10

360k

93.1k

3.01k

4.22k

180pF

1.5µF

62k

5.23k

BYPASS FET

10

0.1µF

59k

44.2k

UV

FLT#

PG

TMR

CONFIG1

GATE1

GATE2

SOURCE

FB

COMM

LTC4238

OV

ISET

CONFIG2

TMRFET

GND

48V

GND

BACKPLANE PLUG-IN

BOARD

SMC5K60A

×4

48V

63A

4238 TA01a

40ms DEBOUNCE

STAGED START

CONTACT BOUNCES

20ms/DIV

4238 TA01b

50V/DIV

50V/DIV

10V/DIV

10V/DIV