Overview
The NCP1395APG, produced by onsemi, is a high-performance resonant mode controller designed to build reliable and rugged switch-mode power supplies. This controller integrates various features to ensure safe and efficient operation, including a high-frequency voltage controller oscillator, adjustable deadtime, and comprehensive protection mechanisms.
It is particularly suited for applications requiring high-frequency operation, adjustable frequency excursion, and robust fault detection and protection. The device supports a wide frequency range from 50 kHz to 1.0 MHz, making it versatile for different power supply designs.
Key Specifications
| Parameter | Typical Value | Unit |
|---|---|---|
| Operating Frequency Range | 50 kHz to 1.0 MHz | Hz |
| Startup Current | 300 mA (directly powered from HV DC rail) | mA |
| Brown-Out Detection Hysteresis Current | 28 mA (NCP1395A), 83 mA (NCP1395B) | mA |
| Minimum and Maximum Frequency Excursion Precision | ±3% (minimum), ±15% (maximum) | % |
| ESD Protection | 2000V (Human Body Model), 200V (Machine Model Method) | V |
| Soft-Start Sequence Activation | Normal startup, back to operation from off state, hiccup faulty mode, brown-out, temperature shutdown | - |
Key Features
- High Frequency Operation: Supports frequencies from 50 kHz up to 1.0 MHz.
- Adjustable Deadtime: Reduces cross-conduction between the upper and lower transistors using a single external resistor.
- Adjustable Soft-Start: Ensures a smooth frequency variation during startup, preventing sudden application of full current to the resonating circuit.
- Adjustable Minimum and Maximum Frequency Excursion: Allows programming of the lowest and highest frequency points using external resistors.
- Low Startup Current: Requires only 300 mA to start up when directly powered from the high-voltage DC rail.
- Brown-Out Detection: Prevents operation from low input voltages and ensures a clean startup sequence with soft-start.
- Adjustable Fault Timer Duration: Allows for customizable fault timer durations using an external capacitor and resistor.
- Cumulative Fault Events: Integrates fault occurrences and adjusts the auto-recovery retry rate.
- Fast and Slow Fault Detection: Includes both immediate and delayed fault detection mechanisms.
- Skip Cycle Possibility: Enables skip cycle implementation for power-saving features.
- Onboard Transconductance Op Amp: Supports constant output current mode or traditional voltage regulation.
Applications
The NCP1395APG is ideal for various power supply applications, including:
- Resonant Mode Power Supplies: Suitable for high-frequency resonant converters requiring robust protection and control features.
- PFC Front-End Circuits: Ensures a clean startup sequence and stabilization of the PFC stage before energizing the resonant tank.
- High-Reliability Power Systems: Used in systems requiring low standby power, adjustable frequency excursion, and comprehensive fault protection.
- Industrial and Consumer Electronics: Applicable in a wide range of electronic devices that demand efficient and reliable power management.
Q & A
- What is the operating frequency range of the NCP1395APG?
The NCP1395APG operates within a frequency range of 50 kHz to 1.0 MHz.
- How does the adjustable deadtime feature work?
The adjustable deadtime is controlled by a single external resistor, which helps reduce cross-conduction between the upper and lower transistors.
- What is the purpose of the soft-start sequence in the NCP1395APG?
The soft-start sequence ensures a smooth frequency variation during startup, preventing sudden application of full current to the resonating circuit.
- How does the brown-out detection feature work?
The brown-out detection prevents operation from low input voltages and ensures a clean startup sequence with soft-start, especially when used with PFC front-end circuits.
- What is the significance of the onboard transconductance op amp?
The onboard transconductance op amp supports constant output current mode or traditional voltage regulation, adding flexibility to the controller's operation.
- How does the fast fault detection mechanism work?
The fast fault input immediately stops all pulses upon detection of a critical fault and remains in that state until the fault is cleared.
- What is the cumulative fault events feature?
The cumulative fault events feature integrates fault occurrences and adjusts the auto-recovery retry rate based on the fault history.
- How can the skip cycle feature be implemented?
The skip cycle feature can be implemented using a simple resistive connection from the feedback pin to the fast fault input.
- What is the purpose of the latch-off protection?
The latch-off protection fully turns off the converter and keeps it latched in case of overvoltage or overtemperature conditions, requiring a power cycle to reset.
- What are the ESD protection levels for the NCP1395APG?
The NCP1395APG has ESD protection levels of 2000V (Human Body Model) and 200V (Machine Model Method).
