特点
Allows Safe Board Insertion and Removal from a Live Backplane
Controls Supply Voltage from 10.8V to 80V
Foldback Current Limiting
Overcurrent Fault Detection
Drives an External N-Channel MOSFET
Programmable Supply Voltage Power-Up Rate
Undervoltage Protection
Latch Off Operation Mode (LT4256-1)
Automatic Retry (LT4256-2)
Available in an 8-Pin SO Package
典型应用
典型应用
描述
The LT ? 4256-1/LT4256-2 are high voltage Hot Swap? controllers that allow a board to be safely inserted and removed from a live backplane. An internal driver drives an external N-channel MOSFET switch to control supply voltages ranging from 10.8V to 80V.
The LT4256-1/LT4256-2 features an adjustable analog foldback current limit. If the supply remains in current limit for more than a programmable time, the N-channel MOSFET shuts off and the PWRGD output asserts low. The LT4256-2 automatically restarts after a time-out delay. The LT4256-1 latches off until the UV pin is cycled low.
The PWRGD output indicates when the output voltage rises above a programmed level. An external resistor string from V CC provides programmable undervoltage protection.
The LT4256 can be used as an upgrade to LT1641 designs. See Table 1 on page 14 for upgraded specifications.
The LT4256-1 and LT4256-2 are available in an 8-pin SO package that is pin compatible with the LT1641.
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