onsemi NCP1395ADR2G

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.

• 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

• LCD/Plasma TV Converters
• High Power AC-DC Adapters for Notebooks
• Industrial and Medical Power Sources
• Offline Battery Chargers

1. 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.
2. What is the switching frequency range of the NCP1395ADR2G?
   The switching frequency range is from 50 kHz to 1.0 MHz.
3. 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.
4. 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.
5. 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.
6. What are the different startup thresholds for the NCP1395A and NCP1395B versions?
   The NCP1395A starts to pulse at V_CC = 12.8 V, while the NCP1395B starts at V_CC = 10 V.
7. 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.
8. 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.
9. 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.
10. 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.