Overview
The UC3854BDWTRG4 is an advanced power factor correction (PFC) controller produced by Texas Instruments. It is a pin-compatible enhanced version of the UC3854, designed to provide all the necessary functions for active power factor corrected preregulators. This 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. This approach maintains stable, low-distortion sinusoidal line current without the need for slope compensation, unlike peak current mode control.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package | 16-pin SOIC (DW) | |
| Operating Temperature Range | 0°C to 70°C | |
| Switching Frequency | 200 kHz | |
| Startup Supply Current | 300 µA | |
| Supply Voltage (VCC) | 10 V to 22 V | |
| VCC Turn-On Threshold | 10.5 V typical | |
| VCC Turn-Off Threshold | 10 V typical | |
| Current Amplifier Bandwidth | 5 MHz typical | |
| Current Amplifier Offset | 0 mV, -4 mV maximum |
Key Features
- 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)
- Low Startup Supply Current (300 µA)
Applications
The UC3854BDWTRG4 is primarily used in power supply systems that require high power factor correction, such as:
- Switch-mode power supplies
- Active power factor corrected (PFC) preregulators
- High-power electronic devices requiring efficient and stable power input
- Industrial and consumer electronics where power quality and efficiency are critical
Q & A
- What is the primary function of the UC3854BDWTRG4?
The primary function of the UC3854BDWTRG4 is to provide active power factor correction for power supply systems, achieving near-unity power factor by shaping the AC input line current waveform to correspond to the AC input line voltage.
- What type of control mode does the UC3854BDWTRG4 use?
The UC3854BDWTRG4 uses fixed-frequency average current-mode control.
- What is the typical switching frequency of the UC3854BDWTRG4?
The typical switching frequency is 200 kHz.
- What is the operating temperature range of the UC3854BDWTRG4?
The operating temperature range is 0°C to 70°C.
- What are the UVLO threshold options for the UC3854BDWTRG4?
The UVLO threshold options are 16 V/10 V for offline and 10.5 V/10 V for startup from an auxiliary 12-V regulator.
- What is the startup supply current of the UC3854BDWTRG4?
The startup supply current is 300 µA.
- What is the bandwidth of the current amplifier in the UC3854BDWTRG4?
The bandwidth of the current amplifier is 5 MHz typical.
- Does the UC3854BDWTRG4 have integrated current and voltage amplifier output clamps?
- What are the key improvements in the UC3854BDWTRG4 compared to its predecessor?
The key improvements include a wide bandwidth, low offset current amplifier, faster responding and improved accuracy enable comparator, VREF GOOD comparator, and enhanced multiply/divide circuit.
- In what package types is the UC3854BDWTRG4 available?
The UC3854BDWTRG4 is available in 16-pin SOIC (DW), PDIP (N), CDIP (J), and 20-pin PLCC (Q) packages.
