Features

• Allows Safe Board Insertion and Removal from a Live Backplane
• Controls Three Supply Voltages from 1.7V to 16.5V with V_CC1 >or= V_CC2 >or= V_CC3
• Programmable Soft-Start with Inrush Current Limiting, No External Gate Capacitor Required
• Faster Turn-Off Time with No Gate Capacitor
• Dual Level Overcurrent Fault Protection
• Programmable Overcurrent Response Time
• Programmable Overvoltage Protection
• Automatic Retry or Latched Mode Operation
• Independent N-Channel FET High Side Drivers
• User-Programmable Supply Voltage Power-Up Rate
• FBn Pin Monitors V_OUTn and Signals RESETn
• Glitch Filter Eliminates Spurious RESETn Signals

Typical Application

Description

The LTC®4230 is a 3-channel Hot Swap™ controller that allows a board to be safely inserted and removed from a live backplane. Internal high side switch drivers control the gates of external N-channel MOSFETs for supply voltages ranging from 1.7V to 16.5V. The LTC4230 provides soft-start and inrush current limiting during the programmable start-up period.

On-chip current limit comparators provide dual level circuit breaker protection. The slow comparators trip at V_CCn–50mV and activate in 10µs or are programmed by an external filter capacitor. The fast comparators trip at V_CCn–150mV and typically respond in 500ns.

Each FBnpin monitors its own output supply voltage and signals its RESET pin. The ON pin turns the chip on and off and can be used for a reset function. The LTC4230 also provides additional functions including fault indication, autoretry or latchoff modes, programmable current limit response time based on the FAULT and FILTER pins’ functionality.