LINEAR TECHNOLOGY - LTC4241 Data Sheet

LTC4241

PCI-Bus with 3.3V Auxiliary Hot Swap Controller

FEATURES DESCRIPTIO Allows Safe Board Insertion and Removal from a The LTC®4241 is a Hot Swap controller that allows a board Live PCI Slot to be safely inserted and removed from a live PCI-bus slot. Controls 3.3V, 5V, –12V, 12V and 3.3V Auxiliary It has a primary controller that controls the four PCI Supplies supplies and an independent auxiliary controller to control

Independent 3.3V Auxiliary Supply Hot Swap TM the 3.3V auxiliary supply. External N-channel transistors Controller are used to control the 3.3V, 5V and 3.3V auxiliary supplies Adjustable Foldback Current Limit with Circuit while on-chip switches control the –12V and 12V supplies. Breaker The 3.3V, 5V and 3.3V auxiliary supplies can be ramped up Adjustable Supply Voltage Power-Up Rate at an adjustable rate. Electronic circuit breakers protect all High Side Drive for External N-Channel FETs five supplies against overcurrent faults. The foldback –12V and 12V On-Chip Switches current limit feature reduces current spikes and power Fault and Power Good Outputs dissipation when shorts occur. The PWRGD output of the primary controller indicates when all four PCI supplies are

APPLICATIO S

within tolerance. The FAULT output indicates an overcurrent condition for any of the five supplies.

PCI-Based Servers Computer Systems The LTC4241 is available in the 20-pin narrow SSOP

package.

, LTC and LT are registered trademarks of Linear Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation.

TYPICAL APPLICATIO

R1 Q1 5V 0.007Ω IRF7413 5A

0.005Ω IRF7413 10Ω

3.3VAUX

0.07Ω Si2306DS 10Ω

SYSTEM 500m A

POWER SUPPLY

AUXIN AUXSENSE AUXGATE 3VIN 3VSENSE GATE 3VOUT 5VIN 5VSENSE 5VOUT GND

12VIN 12V 500m A

VEEIN 12VOUT

AUXON –12V LTC4241 100m A

ON VEEOUT

PCI BACKPLANE

FAULT TIMER CONNECTOR

POWER R9 10k C2 SYSTEM 0.1µF CONTROLLER

PWRGD

LOGIC RESET RESET 4241 F01

Figure 1. Hot Swappable PCI and 3.3V Auxiliary Supplies

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