Overview
The UC3854DWTR-F is a high-power factor preregulator integrated circuit (IC) produced by Texas Instruments. This device is designed to control AC-DC power supplies, ensuring active power factor correction (PFC) and minimizing line-current distortion. The UC3854DWTR-F is part of the UCx854 family, which includes the UC1854, UC2854, and UC3854, each tailored for different operating temperature ranges and applications.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Supply Current, Off | 1.5 | 2 | 2 | mA |
| Supply Current, On | 10 | 16 | 16 | mA |
| VCC Turn-On Threshold | 14.5 | 16 | 17.5 | V |
| VCC Turn-Off Threshold | 9 | 10 | 11 | V |
| ENA Threshold, Rising | 2.4 | 2.55 | 2.7 | V |
| Current Amplifier Bandwidth | - | 1 MHz | - | - |
| Reference Output Voltage | 7.4 | 7.5 | 7.6 | V |
| Operating Temperature Range | 0°C | - | 70°C | - |
Key Features
- Control Boost PWM to 0.99 Power Factor: Ensures high power factor and low distortion.
- Limit Line-Current Distortion to < 5%: Complies with international standards for power quality.
- World-Wide Operation Without Switches: Compatible with various line voltages and frequencies.
- Feedforward Line Regulation: Enhances stability and performance.
- Average Current-Mode Control: Maintains sinusoidal line current without slope compensation.
- Low Noise Sensitivity: High reference voltage and oscillator amplitude minimize noise impact.
- Low Startup Supply Current: Reduces the burden on the power supply circuitry.
- Fixed-Frequency PWM Drive: Supports high-frequency operation.
- Precision Voltage Reference and Analog Multiplier/Divider: Ensures accurate control and regulation.
- 1A Totem-Pole Gate Driver: Compatible with power MOSFETs.
- Over-Current and Low-Supply Detection: Enhances safety and reliability.
Applications
The UC3854DWTR-F is widely used in AC-DC power supplies that require active power factor correction, particularly in applications such as:
- Medical Power Supplies: Ensures compliance with stringent power quality standards.
- Industrial Power Supplies: Optimizes power factor and reduces line-current distortion.
- High-Power Equipment: Meets Class D equipment input current harmonics standards per EN61000-3-2.
Q & A
- What is the primary function of the UC3854DWTR-F IC?
The primary function is to control AC-DC power supplies with active power factor correction and minimize line-current distortion. - What is the operating temperature range of the UC3854DWTR-F?
The operating temperature range is from 0°C to 70°C. - How does the UC3854DWTR-F achieve high power factor?
It uses average current-mode control to maintain a power factor of up to 0.99. - What are the key components of the UC3854DWTR-F?
The IC includes a voltage amplifier, analog multiplier/divider, current amplifier, fixed-frequency PWM, and a power MOSFET compatible gate driver. - What is the significance of the 'F' suffix in UC3854DWTR-F?
The 'F' suffix indicates that this part does not incorporate the Plasma Cleaning Process, unlike the UC3854DWTR without the 'F' suffix. - What standards does the UC3854DWTR-F comply with?
It complies with Class D equipment input current harmonics standards per EN61000-3-2. - How does the UC3854DWTR-F handle noise sensitivity?
It minimizes noise sensitivity through high reference voltage and oscillator amplitude. - What is the role of the soft-start function in the UC3854DWTR-F?
The soft-start function helps in gradually increasing the PWM duty cycle during startup, eliminating turn-on overshoot. - Can the UC3854DWTR-F be used in single and three-phase systems?
Yes, it can be used in both single and three-phase systems with varying line voltages and frequencies. - What is the typical supply current of the UC3854DWTR-F when enabled?
The typical supply current when enabled is 16 mA.
