Linear LTC4444-5高频高压栅极驱动方案

Linear公司的LTC4444-5是高频高压栅极驱动器,能驱动同步DC/DC转换器中两个N-MOSFET,电源电压高达100V.高边栅极上拉电流峰值为1.4A,低边栅极上拉电流峰值为1.75A,具有欠压锁定功能,可用在分布式电源架构,汽车电子电源,大容量电源模块以及通信系统.本文介绍了LTC4444-5的主要特性,方框图以及从36V-72V 输入到48V/6A降压/升压DC/DC转换器电路连接图.

The LTC4444-5 is a high frequency high voltage gate driver that drives two N-channel MOSFETs in a synchronous DC/DC converter with supply voltages up to 100V. The powerful driver capability reduces switching losses in MOSFETs with high gate capacitance. The LTC4444-5’s pull-up for the top gate driver has a peak output current
of 1.4A and its pull-down has an output impedance of 1.5ohm. The pull-up for the bottom gate driver has a peak output current of 1.75A and the pull-down has an output impedance of 0.75ohm.

The LTC4444-5 is configured for two supply-independent inputs. The high side input logic signal is internally level-shifted to the bootstrapped supply, which may function at up to 114V above ground.

The LTC4444-5 contains undervoltage lockout circuits that disable the external MOSFETs when activated. The LTC4444-5 also contains adaptive shoot-through protection to prevent both MOSFETs from conducting simultaneously.

The LTC4444-5 is available in the thermally enhanced 8-lead MSOP package.

主要特性:
■Bootstrap Supply Voltage to 114V
■Wide VCC Voltage: 4.5V to 13.5V
■Adaptive Shoot-Through Protection
■1.4A Peak Top Gate Pull-Up Current
■1.75A Peak Bottom Gate Pull-Up Current
■1.5ohm Top Gate Driver Pull-Down
■0.75ohm Bottom Gate Driver Pull-Down
■5ns Top Gate Fall Time Driving 1nF Load
■8ns Top Gate Rise Time Driving 1nF Load
■3ns Bottom Gate Fall Time Driving 1nF Load
■6ns Bottom Gate Rise Time Driving 1nF Load
■Drives Both High and Low Side N-Channel MOSFETs
■Undervoltage Lockout
■Thermally Enhanced 8-Pin MSOP Package

应用:
■Distributed Power Architectures
■Automotive Power Supplies
■High Density Power Modules
■Telecommunication Systems



图1.LTC4444-5方框图



图2.LTC3780高效36V-72V 输入到48V/6A降压/升压DC/DC转换器电路连接图