1

LTC1645

Dual-Channel Hot Swap

Controller/Power Sequencer

The LTC

allows a board to be safely inserted and removed from a

live backplane. Using external N-channel pass transistors,

the supply voltages can be ramped at a programmable

rate. Two high side switch drivers control the N-channel

gates for supply voltages ranging from 1.2V to 12V. The

two channels can be set to ramp up and down separately,

or they can be programmed to rise and fall simultaneously,

ensuring power supply tracking at the two outputs.

Programmable electronic circuit breakers protect against

shorts at either output. The RESET output can be used to

generate a system reset when a supply voltage falls below

a user-programmed voltage. An additional spare com-

parator is available for monitoring a second supply

voltage.

The LTC1645 is available in the 8- and 14-pin SO packages.

s

Hot Board Insertion

s

Power Supply Sequencing

s

Electronic Circuit Breaker

s

Allows Safe Board Insertion and Removal from a

Live Backplane

s

Programmable Power Supply Sequencing

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Programmable Electronic Circuit Breaker

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User-Programmable Supply Voltage Power-Up and

Power-Down Rate

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High Side Drivers for External N-Channel FETs

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Controls Supply Voltages from 1.2V to 12V

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Ensures Proper Power-Up Behavior

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Undervoltage Lockout

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Glitch Filter Protects Against Spurious RESET Signals

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

Hot Swap is a trademark of Linear Technology Corporation.

5V and 3.3V Hot Swap

5V and 3.3V Hot Swap Waveforms

ON

5V/DIV

GATE

n

10V/DIV

5V/DIV

5V/DIV

0.005

Ω*

IRF7413

IRF7413

0.005

Ω*

10

Ω

10

Ω

10k

5V

5A

3.3V

5A

6

2

3

4

7

8

5

1

1645 TA01

0.01

µF

25V

0.01

µF

25V

ON

ON

GND

GND

PLUG-IN CARD

BACKPLANE

SENSE1

GATE1

SENSE2 GATE2

LTC1645

(8-LEAD)

+

+

*LRF1206-01-R005-J (IRC)

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO