• - 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 UCC2850x family provides all of the control functions necessary for an active power-factor-corrected preregulator and a second-stage dc-to-dc converter. The controller achieves near-unity power factor by shaping the ac input line current waveform to correspond to the ac input-line voltage using average current-mode control. The dc-to-dc converter uses peak current-mode control to perform the step-down power conversion.

The PFC stage is leading-edge modulated while the second stage is trailing-edge synchronized to allow for minimum overlap between the boost and PWM switches. This reduces ripple current in the bulk-output capacitor.In order to operate with over three-to-one range of input-line voltages, a line feedforward (V_FF) is used to keep input power constant with varying input voltage.

特性

• Combines PFC and Downstream Converter Controls
• Controls Boost Preregulator to Near-Unity Power Factor
• Accurate Power Limiting
• Improved Feedforward Line Regulation
• Peak Current-Mode Control in Second Stage
• Programmable Oscillator
• Leading-Edge/Trailing-Edge Modulation for Reduced Output Ripple
• Low Start-up Supply Current
• Synchronized Second Stage Start-Up, with Programmable Soft-start
• Programmable Second Stage Shutdown