LTC1643AL-1

Allows Safe Board Insertion and Removal from a Live PCI Slot
Works on either a Motherboard (LTC1643AH) or CompactPCITM Card (LTC1643AL/LTC1643AL-1)
Controls 12V, 3.3V, 5V, 12V Supplies
Programmable Foldback Current Limit with Circuit Breaker
User-Programmable Supply Voltage Power-Up Rate
High Side Drive for External N-Channel MOSFETs
12V and 12V On-Chip Switches
Fault and Power-Good Outputs
Available in a Narrow 16-Lead SSOP Package

Supply Voltages
12VIN ................................................................ 13.2V
VEEIN ..............................................................13.2V
Input Voltage (Pin 5) .............0.3V to (12VIN + 0.3V)
Output Voltages (Pins 6, 7) ...0.3V to (12VIN + 0.3V)
Analog Voltages
(Pins 3, 4, 9, 10 to 14) ........  .0.3V to (12VIN + 0.3V)
VEEOUT ............................................ 13.2V to + 0.3V
12VOUT .............................................. 0.3V to 13.2V
Operating Temperature Range
LTC1643ALC/LTC1643AL-1C/
LTC1643AHC .............................................0°C to 70
LTC1643ALI/LTC1643AL-1I/
LTC1643AHI ...........................................40 to 85
Storage Temperature Range ................65 to 150
Lead Temperature (Soldering, 10 sec)..................300

The LTC®1643A is a Hot SwapTM controller that allows a board 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. All supply voltages can be ramped up at a programmable rate. An electronic circuit breaker protects all four supplies against overcurrent faults. The foldback current limit feature limits current spikes and power dissipation when shorts occur and allows boards with large capacitances to be powered up without tripping the circuit breaker. The PWRGD output indicates when all of the supply voltages are within tolerance and theFAULT output indicates an overcurrent condition. The O (LTC1643AH)/ON (LTC1643AL/ LTC1643AL-1) pin is used to cycle the board power or reset the circuit breaker. The LTC1643AL-1 has the ±12V power good comparators disabled.

The LTC1643A is available in a 16-pin narrow SSOP packag