NS 公司的LM5035A是集成了半桥和SyncFET驱动器的PWM控制器,包括了采用电压模式控制来实现半桥拓扑功率转换器所需的所有特性,具有105V/2A半桥栅极驱动器,有可编延迟的同步整流器控制输出,电阻编程的2MHz振荡器,可调整软起动,5V基准输出.本文介绍了LM5035A主要特性,方框图, 简化的应用框图和LM5035A评估板的主要特性,应用电路图和材料清单.

    LM5035A: PWM Controller with Integrated Half-Bridge and SyncFET Drivers

    The LM5035A Half-Bridge Controller/Gate Driver contains all of the features necessary to implement half-bridge topology power converters using voltage mode control with line voltage feed-forward. The LM5035A is a functional variant of the LM5035 half-bridge PWM controller. The VCC current limit threshold has been increased to 35 mA. The soft start and soft start currents have been increased from 50 μA to 100 μA. The BST UV threshold has been lowered to less than the VCC UV threshold. The ratio of the T1 and T2 delays on the SR1 and SR2 outputs has been increased from 2:1 to 3:1. The floating high-side gate driver is capable of operating with supply voltages up to 105V. Both the high-side and low-side gate drivers are capable of 2A peak. An internal high voltage startup regulator is included, along with programmable line undervoltage lockout (UVLO) and overvoltage protection (OVP).

    The oscillator is programmed with a single resistor to frequencies up to 2MHz. The oscillator can also be synchronized to an external clock. A current sense input and a programmable timer provide cycle-by-cycle current limit and adjustable hiccup mode overload protection.

    LM5035A主要特性:

    ■ 105V / 2A Half-Bridge Gate Drivers

    ■ Synchronous Rectifier Control Outputs with Programmable Delays

    ■ High Voltage (105V) Start-up Regulator

    ■ Voltage mode Control with Line Feed-Forward and Volt ?Second Limiting

    ■ Resistor Programmed, 2MHz Capable Oscillator

    ■ Patent Pending Oscillator Synchronization

    ■ Programmable Line Under-Voltage Lockout

    ■ Line Over-Voltage Protection

    ■ Internal Thermal Shutdown Protection

    ■ Adjustable Soft-Start

    ■ Versatile Dual Mode Over-Current Protection with Hiccup Delay Timer

    ■ Cycle-by-Cycle Over-Current Protection

    ■ Direct Opto-coupler Interface

    ■ 5V Reference Output

    图1.LM5035A方框图