Overview
The NCP1395BDR2G is a high-performance resonant mode controller produced by onsemi. This device is designed to build reliable and rugged switch-mode power supplies, particularly in resonant applications. It features a unique architecture that includes a 1.0 MHz Voltage Controller Oscillator, providing flexibility and high-frequency operation from 50 kHz to 1.0 MHz. The controller includes various protection features and adjustable parameters to ensure safe and efficient converter operation.
Key Specifications
| Specification | Value |
|---|---|
| Operating Frequency Range | 50 kHz to 1.0 MHz |
| Package Type | 16-Pin SOIC |
| Startup Current | 300 mA (directly powered from high-voltage DC rail), lower threshold with auxiliary supply |
| Startup Thresholds | VCC = 12.8 V (A version), VCC = 10 V (B version) |
| Brown-Out Detection | 28 mA hysteresis current (A version), 83 mA hysteresis current (B version) |
| Adjustable Deadtime | Single resistor adjustable |
| Adjustable Soft-Start | Programmable soft-start sequence |
| Minimum and Maximum Frequency Excursion | Adjustable via external resistors |
| Fast and Slow Fault Detection | Immediate shutdown or timer-based event |
| Onboard Transconductance Op Amp | For constant output current or traditional voltage regulation |
Key Features
- High Frequency Operation: The controller operates from 50 kHz up to 1.0 MHz, providing flexibility in resonant applications.
- Adjustable Deadtime: A single resistor can be used to adjust the deadtime, helping to reduce cross-conduction between the upper and lower transistors.
- Adjustable Soft-Start: The soft-start sequence can be programmed to ensure a smooth startup, activated during normal startup, back to operation from an off state, or during fault conditions.
- Adjustable Minimum and Maximum Frequency Excursion: The minimum and maximum switching frequencies can be set using external resistors to avoid resonating peaks.
- Low Startup Current: The device requires only 300 mA to startup when directly powered from the high-voltage DC rail.
- Brown-Out Detection: Prevents operation from low input voltage, ensuring a clean startup sequence with soft-start.
- Adjustable Fault Timer Duration: A timer can be set to charge an external capacitor, allowing for adjustable fault response times.
- Cumulative Fault Events: The timer capacitor integrates fault occurrences, allowing for auto-recovery retry rate adjustment.
- Fast and Slow Fault Detection: Immediate shutdown or delayed shutdown options based on fault types.
- Skip Cycle Possibility: Easy implementation of skip cycle for power-saving features.
- Onboard Transconductance Op Amp: Allows for various configurations, including constant output current or traditional voltage regulation.
- Broken Feedback Loop Detection: Detects and responds to broken feedback loops, ensuring safe operation.
Applications
The NCP1395BDR2G is suitable for a variety of applications, including:
- Consumer Products: Recommended for the A version, where external startup resistors can be used.
- Industrial and Medical Applications: The B version is more suitable due to its compatibility with 12 V auxiliary supplies.
- Resonant Mode Power Supplies: Ideal for building rugged and safe switch-mode power supplies with low standby power.
- PFC Front-End Circuits: Ensures a clean startup sequence with soft-start, stabilizing the PFC before energizing the resonant tank.
Q & A
- What is the operating frequency range of the NCP1395BDR2G?
The operating frequency range is from 50 kHz to 1.0 MHz.
- What package type does the NCP1395BDR2G come in?
The device comes in a 16-Pin SOIC package.
- What are the startup thresholds for the A and B versions of the NCP1395BDR2G?
The A version starts at VCC = 12.8 V, while the B version starts at VCC = 10 V.
- How does the brown-out detection work in the NCP1395BDR2G?
The brown-out detection prevents operation from low input voltage, with hysteresis currents of 28 mA for the A version and 83 mA for the B version.
- Can the deadtime be adjusted in the NCP1395BDR2G?
Yes, the deadtime can be adjusted using a single resistor.
- What is the purpose of the onboard transconductance op amp?
The onboard transconductance op amp allows for various configurations, including constant output current or traditional voltage regulation.
- How does the fast fault detection work?
The fast fault input immediately stops all pulses when its voltage exceeds 1.0 V, with different restart behaviors for the A and B versions.
- What is the skip cycle feature and how is it implemented?
The skip cycle feature can be implemented by connecting the feedback pin to the fast fault input via a resistive divider, allowing for power-saving features.
- How does the broken feedback loop detection work?
The device detects a broken feedback loop by monitoring the feedback pin voltage and responds by stopping all pulses and waiting for the timer pin voltage to collapse before attempting a restart.
- What are the key differences between the A and B versions of the NCP1395BDR2G?
The main differences include startup thresholds, hysteresis currents, and soft-start behaviors upon fault recovery.
