Overview
The NCP1612A3DR2G is an enhanced, high-efficiency power factor controller (PFC) designed by onsemi. This component is specifically tailored for driving PFC boost stages using the innovative Current Controlled Frequency Fold-back (CCFF) method. It operates in Critical Conduction Mode (CrM) and features a linear frequency decay to minimize stand-by losses. The NCP1612A3DR2G is housed in a SOIC-10 package and incorporates various features necessary for robust and compact PFC stages with minimal external components.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| VCC Range | 9.5 to 35 | V |
| FOVP Pin Range | -0.3 to 10 | V |
| Feedback Pin Range | -0.3 to 10 | V |
| DRV Pin Voltage/Current | -0.3 to 35 V / -500 to 800 mA | V / mA |
| pfcOK Pin Range | -0.3 to VCC | V |
| Maximum Power Dissipation @ TA = 70°C | 550 | mW |
| Thermal Resistance Junction-to-Air | 145 | °C/W |
| Operating Junction Temperature Range | -40 to 125 | °C |
| Typical UVLO Hysteresis | 1.5 V | V |
| Maximum Dead-time | 48.5 µs | µs |
| Thermal Shutdown Threshold | 150 | °C |
Key Features
- Near-unity Power Factor
- Critical Conduction Mode (CrM)
- Current Controlled Frequency Fold-back (CCFF): Low Frequency Operation at Low Current Levels
- On-time Modulation for Proper Current Shaping in CCFF Mode
- Skip Mode Near the Line Zero Crossing
- Fast Line/Load Transient Compensation (Dynamic Response Enhancer)
- Valley Turn On
- High Drive Capability: -500 mA/+800 mA
- Low Start-up Consumption
- Soft Over-voltage Protection
- Brown-out Detection
- Soft-start for Smooth Start-up Operation
- Over Current Limitation
- Thermal Shutdown
- Latched Off Capability
- Open Ground Pin Fault Monitoring
- Saturated Inductor Protection
Applications
- PC Power Supplies
- All Off Line Appliances Requiring Power Factor Correction
- AC-DC Adapters
- Flat TVs
- Lighting Systems
Q & A
- What is the primary function of the NCP1612A3DR2G? The NCP1612A3DR2G is a power factor controller designed to drive PFC boost stages using the Current Controlled Frequency Fold-back (CCFF) method.
- What package type does the NCP1612A3DR2G come in? The NCP1612A3DR2G is housed in a SOIC-10 package.
- What is the VCC range for the NCP1612A3DR2G? The VCC range is from 9.5 V to 35 V.
- What are the key safety features of the NCP1612A3DR2G? Key safety features include Fast Over-voltage Protection (FOVP), Soft Over-voltage Protection, Brown-out Detection, Over Current Limitation, Thermal Shutdown, and Latched Off Capability.
- What is the purpose of the pfcOK pin? The pfcOK pin is grounded until the PFC output has reached its nominal level and is also grounded if the NCP1612 detects a fault.
- What are the typical applications for the NCP1612A3DR2G? Typical applications include PC power supplies, off-line appliances requiring power factor correction, AC-DC adapters, flat TVs, and lighting systems.
- How does the CCFF method improve efficiency? The CCFF method maximizes efficiency at both nominal and light loads by linearly decaying the frequency down to about 20 kHz when the inductor current is null, reducing stand-by losses to a minimum.
- What is the significance of the Dynamic Response Enhancer (DRE)? The DRE drastically speeds up the loop response when the output voltage drops below 95.5% of the desired output level.
- What versions of the NCP1612 are available? There are six versions: NCP1612A, NCP1612B, NCP1612A1, NCP1612A2, NCP1612A3, and NCP1612B2.
- How does the NCP1612A3DR2G handle thermal issues? The NCP1612A3DR2G includes thermal shutdown with a threshold of 150°C and a hysteresis of 50°C.
