UC3827N-1

降电流/电压馈送推挽PWM控制器 Buck Current/Voltage Fed Push-Pull PWM Controllers

DESCRIPON

The UC3827 family of controller devices provides an integrated control solution for cascaded buck and push-pull converters. These converters are known as current fed or voltage fed push-pull converters and are ideally suited for multiple output and/or high voltage output applications. In both current fed and voltage fed modes, the push-pull switches are driven at 50% nominal duty cycles and at one half the switching frequency of the buck stage. In the current fed mode, the two switches are driven with a specified over-lap period to prevent ringing and voltage stress on the devices. In the voltage fed mode, the two switches are driven with a specified gap time between the switches to prevent shorting the transformer across the energy storage capacitor and to prohibit excessive currents flowing through the devices.

FEATURES

• Ideal for Multiple Output and/or High Voltage Output Voltage Converters

• Up to 500 kHz Operation

• High Voltage, High Current Floating Driver for Buck Converter Stage

• UC3827-1 Current Fed Controller has Push-Pull Drivers with Overlapping Conduction Periods

• UC3827-2 Voltage Fed Controller has Push-Pull Drivers with Nonoverlapping Conduction Periods

• Average Current Mode, Peak Current Mode or Voltage Mode with Input Voltage Feedforward Control for Buck Power Stage

• Wide Bandwidth, Low Offset, Differential Current Sense Amplifier

• Precise Short Circuit Current Control