器件名称: UC2548
功能描述: Primary Side PWM Controller
文件大小: 345.55KB 共9页
简 介:UC1548 UC2548 UC3548
Primary Side PWM Controller
FEATURES
Primary Side Voltage Feedforward Control of Isolated Power Supplies Accurate DC Control of Secondary Side Short Circuit Current using Primary Side Average Current Mode Control Accurate Programmable Maximum Duty Cycle Clamp Maximum Volt-Second Product Clamp to Prevent Core Saturation Practical Operation Up to 1MHz High Current (2A Pk) Totem Pole Output Driver Wide Bandwidth (8MHz) Current Error Amplifier Undervoltage Lockout Monitors VCC, VIN and VREF Output Active Low During UVLO Low Startup Current (500A)
BLOCK DIAGRAM
UDG-95037
DESCRIPTION
Pin numbers refer to 16-pin DIL and SOIC packages only.
The UC3548 family of PWM control ICs uses voltage feedforward control to regulate the output voltage of isolated power supplies. The UC3548 resides on the primary side and has the necessary features to accurately control secondary side short circuit current with average current mode control techniques. The UC3548 can be used to control a wide variety of converter topologies. In addition to the basic functions required for pulse width modulation, the UC3548 implements a patented technique of sensing secondary current from the primary side in an isolated buck derived converter. A current waveform synthesizer monitors switch current and simulates the inductor current downslope so that the complete current waveform can be constructed on the primary side without actual secondary side measurement. This information ……
