• - 交流-直流(AC-DC)控制器和稳压器
• - 直流-直流(DC-DC)控制器、转换器和稳压器
• - 电压和电流管理
• - 通讯IC
• - 驱动器
• - 热管理

• - 时钟及数据分配
• - 标准逻辑

• - 放大器和比较器
• - 模拟开关
• - 数字电位计
• - 接口
• - EMI和RFI滤波器

• - EEPROM存储器
• - 非易失性只读存储器(NVRAM)
• - SRAM存储器

说明

The UC3848 family of PWM control ICs makes primary side average current mode control practical for isolated switching converters. Average current mode control insures that both cycle by cycle peak switch current and maximum average inductor current are well defined and will not run away in a short circuit situation. The UC3848 can be used to control a wide variety of converter topologies.

In addition to the basic functions required for pulse width modulation, the UC3848 implements a patented technique of sensing secondary current in an isolated buck derived converter from the primary side. A current wave-form synthesizer monitors switch current and simulates the inductor current down slope so that the complete current waveform can be constructed on the primary side without actual secondary side measurement.

特性

• Practical Primary Side Control of Isolated Power Supplies with IC Control of Secondary Side Current
• 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
• Under Voltage Lockout Monitors VCC, VIN and VREF
• Output Active Low During UVLO
• Low Startup Current (500µA)
• Precision 5V Reference (1%)