1

LTC1642A

1642af

Hot Swap Controller

Protection

■

Against Surges to 33V

■

Latch Off or Automatic Retry on Current Fault

■

Reference Output with Uncommitted Comparator

1N4705

18V

12V

BACKPLANE

(SHORT PIN)

PLUG-IN CARD

SENSE

GATE

GND BRK TMR

LTC1642A

RST TMR

ON

FAULT

OV

RESET

FB

CRWBR

0.33

µF

0.33

µF

2N2222

MCR

12DC

REF

0.1

µF

2.87k

1%

110k

1%

100

Ω

5%

107k

1%

13k

1%

FDS6630A

0.01

µF

0.047

µF

12V

AT 2.5A

330

Ω

5%

0.010

Ω

5%

11.3k

1%

POWER-GOOD = 11.4V

1642a TA01

+

COMPOUT

GND

UV = 10.8V

OV = 13.2V

APPLICATIO S

FEATURES

TYPICAL APPLICATIO

The LTC

allows a board to be safely inserted and removed from a

live backplane. Using an external N-Channel pass transis-

tor, the board supply voltage can be ramped up at an

adjustable rate. A high side switch driver controls the

N-Channel gate for supply voltages ranging from 2.97V

to 16.5V.

The SENSE pin allows foldback limiting of the load current,

with circuit breaker action after an adjustable delay time.

The delay allows the part to power-up in current limit. The

CRWBR output can be used to trigger an SCR for crowbar

protection of the load if the input supply exceeds an

adjustable threshold. The RESET output can generate a

system reset with adjustable delay when the supply volt-

age falls below an adjustable threshold. The ON pin cycles

the board power. The LTC1642A is available in the 16-pin

SSOP package.

DESCRIPTIO

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

trademarks are the property of their respective owners. Hot Swap is a trademark of Linear

Technology Corporation.