Overview
The NCP1395ADR2G, produced by onsemi, is a high-performance resonant mode controller designed to build reliable and rugged switch-mode power supplies. This controller features a unique architecture with a 1 MHz Voltage Controller Oscillator, providing flexibility in various applications, including those requiring ORing functions and multiple feedback paths. It includes comprehensive protection features such as immediate shutdown, timer-based events, brown-out detection, and broken optocoupler detection, ensuring a safer converter design without adding complexity. The device also includes an on-board operational transconductance amplifier for various configurations, including constant output current and traditional voltage regulation.
Key Specifications
| Parameter | Value |
|---|---|
| Control Mode | Voltage Mode |
| Switching Frequency Range | 50 kHz to 1.0 MHz |
| Minimum Switching Frequency Accuracy | ±3% |
| Adjustable Deadtime | 150 ns to 1.0 µs |
| Startup Current | 300 µA max |
| UVLO (Under Voltage Lock Out) | 12.8 V (NCP1395A), 10 V (NCP1395B) |
| Short Circuit Protection | Latched |
| Soft Start | Adjustable |
| VCC Max | 20 V |
| Drive Capacity | 180 / 180 mA |
| Package Type | SOIC-16 |
Key Features
- High Frequency Operation from 50 kHz up to 1.0 MHz
- Selectable Minimum Switching Frequency with ±3% Accuracy
- Timer-Based Input with Auto-Recovery Operation for Delayed Event Reaction
- Adjustable Deadtime from 150 ns to 1.0 µs
- Startup Sequence via an Adjustable Soft-Start
- Brown-Out Protection for Simpler PFC Association
- Latched Input for Severe Fault Conditions (e.g., Overtemperature or OVP)
- Enable Input for Immediate Event Reaction or Simple ON/OFF Control
- Operational Transconductance Amplifier (OTA) for Multiple Feedback Loops
- Low Startup Current of 300 µA max
- Common Collector Optocoupler Connection
- Fast and Slow Fault Detection
- Skip Cycle Possibility
- Broken Feedback Loop Detection
Applications
- LCD/Plasma TV Converters
- High Power AC-DC Adapters for Notebooks
- Industrial and Medical Power Sources
- Offline Battery Chargers
Q & A
- What is the primary function of the NCP1395ADR2G?
The NCP1395ADR2G is a high-performance resonant mode controller designed to build reliable and rugged switch-mode power supplies. - What is the switching frequency range of the NCP1395ADR2G?
The switching frequency range is from 50 kHz to 1.0 MHz. - What types of protection features does the NCP1395ADR2G include?
The device includes protections such as immediate shutdown, timer-based events, brown-out detection, and broken optocoupler detection. - How does the adjustable deadtime feature work?
The adjustable deadtime, set via a single resistor wired to ground, helps in reducing the shoot-through current contribution as the switching frequency increases. - What is the purpose of the on-board operational transconductance amplifier?
The on-board operational transconductance amplifier allows for various configurations, including constant output current working mode or traditional voltage regulation. - What are the different startup thresholds for the NCP1395A and NCP1395B versions?
The NCP1395A starts to pulse at VCC = 12.8 V, while the NCP1395B starts at VCC = 10 V. - How does the brown-out detection feature work?
Brown-out detection prevents the controller from switching if the high-voltage rail is not within the right boundaries, ensuring a clean startup sequence with soft-start. - What is the purpose of the fast and slow fault inputs?
The fast fault input immediately stops all pulses for critical faults, while the slow fault input serves as a delayed shutdown for transient overloads. - How does the skip cycle feature work?
The skip cycle feature can be implemented through a simple resistive connection from the feedback pin to the fast fault input, allowing power-saving features. - What happens when the feedback loop is broken?
If the feedback loop is broken, the timer starts to charge a capacitor, and if the loop is not restored, the controller stops all pulses and waits for the timer pin voltage to collapse before attempting a restart.
