Overview
The NCP1239ED65R2G is a fixed-frequency current-mode controller designed by onsemi, specifically tailored for use in flyback converters. This component features a high-voltage start-up current source, which enables a quick and lossless power-on sequence, simplifying the design of the auxiliary supply and VCC capacitor. It operates at a fixed frequency of 65 kHz and includes various protection mechanisms and efficiency-enhancing features.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Frequency | 65 kHz | |
| Power Supply Voltage (VCC Pin) | -0.3 to 35 | V |
| Maximum Voltage on Low Power Pins (CS, FB, Fault) | -0.3 to 5.5 | V |
| Maximum Voltage on DRV Pin | -0.3 to 20 | V |
| High Voltage Pin (HV) | -0.3 to 650 | V |
| Thermal Resistance Junction-to-Air | 250 | °C/W |
| Maximum Junction Temperature | 150 | °C |
| Storage Temperature Range | -60 to 150 | °C |
| ESD Capability (Human Body Model) | 4 kV | |
| ESD Capability (Machine Model) | 200 V | |
| ESD Capability (Charged-Device Model) | 1 kV | |
| Moisture Sensitivity Level | 1 | |
| Peak Sink Current (DRV Low State) | -500 mA | mA |
| Start-Up Threshold (VCC Increasing) | 11.0 to 13.0 | V |
| Frequency Foldback Transition Frequency | 22 to 30 kHz | kHz |
Key Features
- Fixed-Frequency 65-kHz Current-Mode Control Operation: Ensures stable and efficient operation.
- Frequency Foldback Down to 26 kHz and Skip Mode: Maximizes performance in light load conditions.
- Adjustable Over Power Protection (OPP) Circuit: Provides customizable protection against over-power conditions.
- High-Voltage Current Source with Brown-Out (BO) Detection: Facilitates quick and lossless power-on sequences.
- Internal Slope Compensation: Enhances stability and prevents sub-harmonic oscillations.
- Internal Fixed Soft-Start: Reduces inrush current during startup.
- Frequency Jittering in Normal and Frequency Foldback Modes: Improves EMI performance.
- 64-ms Timer-Based Short-Circuit Protection with Auto-Recovery or Latched Operation: Provides robust protection against short-circuit conditions.
- Latched OVP on VCC – Auto-Recovery for C and E Versions: Ensures converter protection with automatic recovery.
- Latched OVP/OTP Input for Improved Robustness: Enhances overall system reliability.
- Internal Thermal Shutdown: Protects the device from overheating.
- Extremely Low No-Load Standby Power: Minimizes power consumption in standby mode.
- Pin-to-Pin Compatible with the Existing NCP1236/1247 Series: Simplifies design transitions and upgrades.
- Pb-Free and RoHS Compliant: Meets environmental and regulatory standards.
Applications
- AC-DC Converters for TVs, Set-Top Boxes, and Printers
- Offline Adapters for Notebooks and Netbooks
Q & A
- What is the operating frequency of the NCP1239ED65R2G?
The NCP1239ED65R2G operates at a fixed frequency of 65 kHz.
- What is the maximum voltage rating for the VCC pin?
The maximum voltage rating for the VCC pin is 35 V.
- What protection mechanisms does the NCP1239ED65R2G include?
The device includes over-power protection (OPP), over-voltage protection (OVP), over-temperature protection (OTP), and short-circuit protection.
- How does the frequency foldback feature work?
The frequency foldback feature reduces the switching frequency down to 26 kHz and enters skip cycle mode as the power on the secondary side decreases, maximizing efficiency in light load conditions.
- What is the purpose of the internal high-voltage start-up current source?
The internal high-voltage start-up current source provides a quick and lossless power-on sequence, simplifying the design of the auxiliary supply and VCC capacitor.
- Is the NCP1239ED65R2G Pb-Free and RoHS compliant?
- What is the maximum junction temperature for the NCP1239ED65R2G?
The maximum junction temperature is 150°C.
- What is the storage temperature range for the NCP1239ED65R2G?
The storage temperature range is -60 to 150°C.
- Does the NCP1239ED65R2G have internal thermal shutdown?
- What are the typical applications for the NCP1239ED65R2G?
