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LTC1643L/LTC1643L-1/LTC1643H

PCI-Bus Hot Swap

Controller

Hot Swappable PCI Supply

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Allows Safe Board Insertion and Removal from a

Live PCI Slot

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Works on either a Motherboard (LTC1643H) or

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Controls –12V, 3.3V, 5V, 12V Supplies

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Programmable Foldback Current Limit with

Circuit Breaker

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User-Programmable Supply Voltage Power-Up Rate

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High Side Drive for External N-Channel MOSFETs

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–12V and 12V On-Chip Switches

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Fault and Power-Good Outputs

to be safely inserted and removed from a live PCI-Bus slot.

Two external N-channel transistors control the 3.3V and 5V

supplies while on-chip switches control the –12V and 12V

supplies.Allsupplyvoltagescanberampedupataprogram-

mable rate. An electronic circuit breaker protects all four

suppliesagainstovercurrentfaults.Thefoldbackcurrentlimit

feature limits current spikes and power dissipation when

shortsoccurandallowsboardswithlargecapacitancestobe

poweredupwithouttrippingthecircuitbreaker.ThePWRGD

output indicates when all of the supply voltages are within

tolerance and the FAULT output indicates an overcurrent

condition.The ON(LTC1643H)/ON (LTC1643L/LTC1643L-1)

pin is used to cycle the board power or reset the circuit

breaker. The LTC1643L-1 has the

±12V power good com-

parators disabled.

The LTC1643 is available in a 16-pin narrow SSOP package.

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PCI-Based Servers

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CompactPCI Compliant Boards

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

Hot Swap is a trademark of Linear Technology Corporation.

CompactPCI is a trademark of PCI Industrial Computer Manufacturing Group.

FEATURES

DESCRIPTIO

APPLICATIO S

R2

0.005

Ω

Q2

IRF7413

Q1

IRF7413

R1

0.007

Ω

R5

10

Ω

R6

10

Ω

R7

100

Ω

C1

0.047

µF

5V

5A

3.3V

7.6A

GND

–12V

100mA

12V

500mA

R3

10k

R4

10k

11

3

13

12

14

16

15

4

10

9

8

1

2

5

6

7

GND

ON

FAULT

PWRGD

LTC1643H

TIMER

GATE

1643 TA01

SYSTEM

POWER

SUPPLY

PCI

POWER

SYSTEM

CONTROLLER

C2

0.1

µF

RESET

LOGIC

RESET

FOR INFORMATION PURPOSES ONLY

OBSOLETE:

Contact Linear Technology for Potential Replacement