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.

Available in the 16-pin N (PDIP), DW (SOIC Wide), and J (CDIP) and 20-pin Q (PLCC) package. See Ordering Information table for availability by temperature range.

The UC3854A/B products improve upon the UC3854 by offering a wide bandwidth, low offset current amplifier, a faster responding and improved accuracy enable comparator, a VREF GOOD comparator, UVLO threshold options (16 V/10 V for offline, 10.5 V/10 V for startup from an auxiliary 12-V regulator), lower startup supply current, and an enhanced multiply/divide circuit. New features like the amplifier output clamps, improved amplifier current sinking capability, and low offset VAC pin reduce the external component count while improving performance. Improved common mode input range of the multiplier output/current amplifier input allow the designer greater flexibility in choosing amethod for current sensing. Unlike its predecessor, R_SET controls only oscillator charging current and has no effect on clamping the maximum multiplier output current. This current is now clamped to a maximum of 2 × I_AC at all times which simplifies the design process and provides foldback power limiting during brownout and extreme low line conditions.

• 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 VAC Offset (Eliminates External Resistor), 0 V to 5 V Multout Common-Mode Range
• VREF 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

• Topology
• Boost
• Control mode
• CCM
• Practical operating frequency (Max) (MHz)
• 0.2
• UVLO thresholds on/off (V)
• 10.5/10
• Device type
• Controllers
• Operating supply current (mA)
• 12
• Features
• > 750W Applications, Average Current Mode, Continuous Control Mode , Enable, OVP
• Rating
• Military
• Operating temperature range (C)
• -40 to 85

UC2854M的完整型号有：UC2854J，以下是这些产品的关键参数及官网采购报价：

UC2854J，工作温度：-40 to 85，封装：CDIP (J)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网UC2854J的批量USD价格：11.411（1000+）

UC2854J，工作温度：-40 to 85，封装：CDIP (J)-16，包装数量MPQ：1个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：SNPB，TI官网UC2854J的批量USD价格：11.411（1000+）