• - 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 UC3854A/B products are pin compatibleenhanced versions of the UC3854. Like the UC3854, these products provide all of the functions necessary for active power factor corrected preregulators. The controller achieves near unity power factor by shaping the ac input line current waveform to correspond to the ac input line voltage. To do this the UC3854A/B uses average current mode control. Average current mode control maintains stable, low distortion sinusoidal line current without the need for slope compensation, unlike peak current mode control.

A 1%, 7.5-V reference, fixed frequency oscillator, PWM, voltage amplifierwith soft-start, line voltage feedforward (V_RMS squarer), input supply voltage clamp, and over current comparator round out the lilst of feataures.

特性

• Controls Boost PWM to Near-Unity Power Factor
• Limits Line Current Distortion To <3%
• World-Wide Operation Without Switches
• Accurate Power Limiting
• Fixed-Frequency Average Current-Mode Control
• High Bandwidth (5 MHz), Low-Offset Current Amplifier
• Integrated Current- and Voltage-Amplifier Output Clamps
• Multiplier Improvements: Linearity, 500 mV V_AC Offset (Eliminates External Resistor), 0 V to 5 V Multout Common-Mode Range
• V_REF GOOD Comparator
• Faster and Improved Accuracy ENABLE Comparator
• UVLO Options (16 V/10 V or 10.5 V/10 V)
• 300-µA Start-Up Supply Current