UC3854N High Power Factor Preregulator 
DataSheet
Description
The UC3854 provides active power factor correction for power systems that otherwise would draw non-sinusoidal current from sinusoidal power lines. This device implements all the control functions necessary to build a power supply capable of optimally using available power-line current while minimizing line-current distortion. To do this, the UC3854 contains a voltage amplifier, an analog multiplier/divider, a current amplifier, and a fixed-frequency PWM. In addition, the UC3854 contains a power MOSFET compatible gate driver, 7.5V reference, line anticipator, load-enable comparator, low-supply detector, and over-current comparator.
The UC3854 uses average current-mode control to accomplish fixed-frequency current control with stability and low distortion
Features
- Control Boost PWM to 0.99 Power Factor
- Limit Line Current Distortion To <5%
- World-Wide Operation Without Switches
- Feed-Forward Line Regulation
- Average Current-Mode Control
- Low Noise Sensitivity
- Low Start-Up Supply Current
- Fixed-Frequency PWM Drive
- Low-Offset Analog Multiplier/Divider
- 1A Totem-Pole Gate Driver
- Precision Voltage Reference
- Compatibility: UC1854, UC2854
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Specifications:
| UVLO Thresholds On/Off (V) |
16/10 |
| Operating Supply (Max) (V) |
30 |
| Startup Current (mA) |
1.5 |
| Operating Supply Current (mA) |
10 |
| Vref (V) |
7.5 |
| Vref tol (%) |
1.3 |
| Duty Cycle (Max) (%) |
95 |
| Practical Operating Frequency (Max) (MHz) |
0.2 |
| Pin / Package |
16PDIP |
| Update on www.tme.vn |
12 / 04 / 2012 |
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