Features

• Allows Safe Board Insertion and Removal from a Live Backplane
• Controls Supply Voltages from 2.5V to 16.5V
• Adjustable Soft-Start with Inrush Current Limiting
• Fast Turn-Off Time
• No External Gate Capacitor is Required
• Power Good Input with Adjustable Timer and Glitch Filter
• Power-Up Timeout Circuit Interfaces with External Supply Monitors
• Dual Level Overcurrent Fault Protection
• Automatic Retry or Latched Mode Operation
• High Side Drive for an External N-Channel FET
• MS10 Package

Typical Application

Description

The LTC®4212 is a Hot Swap™ controller that allows a board to be safely inserted and removed from a live backplane. An internal high side switch driver controls the gate of an external N-channel MOSFET for supply voltages ranging from 2.5V to 16.5V. The LTC4212 provides soft-start and inrush current limiting during the start-up period. It features a power-up timeout circuit that disconnects the system supply when the onboard supplies do not enter into regulation within an adjustable timeout period. The controller interfaces with external supply monitor ICs or directly with the PGOOD pin of a DC/DC converter. After normal power-up, a programmable power good glitch filter can be enabled to filter out short term dips in the supplies.

Two current limit comparators provide dual level overcurrent circuit breaker protection. The slow comparator trips at V_CC – 50mV and activates in 18µs. The fast comparator trips at V_CC – 150mV and typically responds in 500ns.

The LTC4212 can be configured for both latchoff and autoretry applications and is available in a 10-pin MSOP package.