LTC1421 Datasheet

• Allows Safe Board Insertion and Removal from a Live Backplane
• System Reset and Power Good Control Outputs
• Programmable Electronic Circuit Breaker
• User Programmable Supply Voltage Power-Up Rate
• High Side Driver for Two External N-Channels
• Controls Supply Voltages from 3V to 12V
• Connection Inputs Detect Board Insertion or Removal
• Undervoltage Lockout
• Power-On Reset Input

• Hot Board Insertion
• Electronic Circuit Breaker

The LTC1421 are Hot Swap^™ controllers that allow a board to be safely inserted and removed from a live backplane. Using external N-channel pass transistors, the board supply voltages can be ramped up at a programmable rate. Two high side switch drivers control the N-channel gates for supply voltages ranging from 3V to 12V.

A programmable electronic circuit breaker protects against shorts. Warning signals indicate that the circuit breaker has tripped, a power failure has occurred or that the switch drivers are turned off. The reset output can be used to generate a system reset when the power cycles or a fault occurs. The two connect inputs can be used with staggered connector pins to indicate board insertion or removal. The power-on reset input can be used to cycle the board power or clear the circuit breaker.

The trip point of the ground sense comparator is set at 0.1V for LTC1421.

The LTC1421 are available in 24-pin SO and SSOP packages.