LTC4449

High Speed Synchronous N-Channel MOSFET Driver

* 4V to 6.5V VCC Operating Voltage

* 38V Maximum Input Supply Voltage

* Adaptive Shoot-Through Protection

* Rail-to-Rail Output Drivers

* 3.2A Peak Pull-Up Current

* 4.5A Peak Pull-Down Current

* 8ns TG Rise Time Driving 3000pF Load

* 7ns TG Fall Time Driving 3000pF Load

* Separate Supply to Match PWM Controller

* Drives Dual N-Channel MOSFETs

* Undervoltage Lockout

* Low Profile (0.75mm) 2mm × 3mm DFN Package

The LTC4449 is a high frequency gate driver that is designed to drive two N-Channel MOSFETs in a synchronous DC/DC converter. The powerful rail-to-rail driver capability reduces switching losses in MOSFETs with high gate capacitance. The LTC4449 features a separate supply for the input logic to match the signal swing of the controller IC. If the input signal is not being driven, the LTC4449 activates a shutdown mode that turns off both external MOSFETs. The input logic signal is internally level-shifted to the bootstrapped supply, which functions at up to 42V above ground. The LTC4449 contains undervoltage lockout circuits on both the driver and logic supplies that turn off the external MOSFETs when an undervoltage condition is present. An adaptive shoot-through protection feature is also built-in to prevent the power loss resulting from MOSFET cross-conduction current. The LTC4449 is available in the 2mm × 3mm DFN package. Applications

* Distributed Power Architectures

* High Density Power Modules