LTC4238 Datasheet

• Allows Safe Board Insertion into Live Backplane
• Wide Operating Voltage Range: 6.5V to 80V
• Drives Two Gates for High Power Applications
• Configurable Parallel, Staged Start or Single MOSFET Modes
• Adjustable Precision Current Limit: 6mV to 20mV
• Current Foldback Limits MOSFET Power
• SOA Timer Optimizes MOSFET Capability
• Monitors V_GS and V_DS for MOSFET Health
• 12V Gate Drive for Lower MOSFET R_DS(ON)
• Parallelable Controllers for Very High Current Levels
• Available in 24-Lead Narrow SSOP and 24-Pin 4mm × 5mm QFN Packages

• Live Board Insertion in 12V, 24V and 48V Systems
• Industrial High Side Switch/Circuit Breaker
• Computers, Servers
• Vehicle Electrical Systems

The LTC4238 is a high voltage high current Hot Swap controller that allows a board to be safely inserted and removed from a live backplane. Dual 12V gate drive is well suited for high power applications to either share safe operating area across parallel MOSFETs or support a 2-stage start-up that first charges the load capacitance followed by enabling a low on-resistance path to the load.

The device features active current limiting (ACL) with two foldback options as VDS increases. The constant power profile limits the power dissipation to be no higher than a fixed value, while the high power profile allows the part to ride through large input steps during operation.

The LTC4238 notifies when output power is good. In addition, it has protection features that respond to input undervoltage, overvoltage; and generate a fault when there is an overcurrent or FET bad condition.