TI公司的LM5045是一款可实现电流模式或电压模式的全桥式拓扑PWM功率控制转换器芯片,该芯片主要解决输入最高电压达100V的原级隔离DC-DC转换器。具有电流限制、可编程软启动、同步整流软启动和热关断等特性。本文首先介绍芯片的简介、特性及内部框图,并给出相应设计方案的设计原理图、元器件列表及PCB元件布局图。
The LM5045 PWM controller contains all of the features necessary to implement Full-Bridge topology power converters using either current mode or voltage mode control. This device is intended to operate on the primary side of an isolated dc-dc converter with input voltage up to 100V. This highly integrated controller-driver provides dual 2A high and low side gate drivers for the four external bridge MOSFETs plus control signals for the secondary side synchronous rectifier MOSFETs. External resistors program the leading and trailing edge dead-time between the main and synchronous rectifier control signals. Intelligent startup of the synchronous rectifiers allows monotonic turn-on of the power converter even with pre-bias load conditions.Additional features include cycle-by-cycle current limiting, hiccup mode restart, programmable soft start, synchronous rectifier soft-start and a 2 MHz capable oscillator with synchronization capability and thermal shutdown.
LM5045主要特性:
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