Overview
The NCP1377BD1R2G, produced by onsemi, is a PWM Current-Mode Controller designed for free-running quasi-resonant operation. This controller combines a true current-mode modulator and a demagnetization detector, ensuring full borderline/critical conduction mode in various load and line conditions. It features minimum drain voltage switching, reducing EMI and video noise perturbations. The NCP1377BD1R2G is particularly suited for low-cost AC-DC adapters, consumer electronics, and auxiliary power supplies due to its high-performance high-voltage technology and low part count.
Key Specifications
| Characteristic | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 11.0 | 12.0 | 13.5 | V |
| High-Voltage Pin (HV) | 20 | 23.5 | 500 | V |
| Output Voltage Rise-Time @ CL = 1.0 nF | 40 | - | - | ns |
| Output Voltage Fall-Time @ CL = 1.0 nF | 20 | - | - | ns |
| Source Resistance | 12 | 20 | 36 | Ω |
| Sink Resistance | 5.0 | 10 | 19 | Ω |
| Maximum Internal Current Setpoint | 0.9 | 1.0 | 1.1 | V |
| Propagation Delay from Current Detection to Gate OFF State | 100 | 160 | - | ns |
| Leading Edge Blanking Duration | 380 | - | - | ns |
| Internal Timer Duration (NCP1377B) | - | 3.0 | - | μs |
| Internal Soft-Start Time | - | 1.0 | - | ms |
| Maximum Junction Temperature | - | - | 150 | °C |
| Storage Temperature Range | -60 | - | 150 | °C |
Key Features
- Free-Running Borderline/Critical Mode Quasi-Resonant Operation: Ensures efficient operation with minimal primary switch turn-on losses and secondary diode recovery losses.
- Latched Overvoltage Protection (OVP): The IC permanently latches off in case of an overvoltage condition, requiring a VCC cycle down to 4.0 V to reset.
- Auto-Recovery Short-Circuit Protection via UVLO Crossover: The device stops switching pulses and enters a safe burst mode during short-circuit conditions, auto-recovering once the fault is cleared.
- External Latch Triggering: Allows external signals, such as from a temperature sensor, to latch off the IC.
- Current-Mode with Adjustable Skip Cycle Capability: The skip cycle level can be adjusted, and the controller enters burst mode at low power demand to avoid audible noise.
- Internal 1.0 ms Soft-Start: Reduces startup stress by gradually increasing the output voltage.
- Internal Temperature Shutdown: Protects the device from overheating by shutting down at high temperatures.
- Transformer Core Reset Detection: Ensures discontinuous operation and provides overvoltage detection through an auxiliary winding.
Applications
The NCP1377BD1R2G is ideal for various applications, including:
- Low-Cost AC-DC Adapters: Due to its high-performance and low part count, it is well-suited for cost-effective power supply designs.
- Consumer Electronics: Used in a wide range of consumer electronic devices requiring efficient and reliable power management.
- Auxiliary Power Supplies: Suitable for auxiliary power supplies in various electronic systems.
Q & A
- What is the primary function of the NCP1377BD1R2G?
The NCP1377BD1R2G is a PWM Current-Mode Controller designed for free-running quasi-resonant operation in switch-mode power supplies.
- What are the key benefits of quasi-resonant operation in the NCP1377BD1R2G?
Quasi-resonant operation reduces EMI and video noise perturbations by restarting the MOSFET in the minimum of the drain-source wave.
- How does the NCP1377BD1R2G handle overvoltage conditions?
The IC features latched overvoltage protection, which permanently latches off the device in case of an overvoltage condition, requiring a VCC cycle down to 4.0 V to reset.
- What is the purpose of the internal soft-start feature?
The internal 1.0 ms soft-start reduces startup stress by gradually increasing the output voltage.
- How does the NCP1377BD1R2G protect against short-circuit conditions?
The device stops switching pulses and enters a safe burst mode during short-circuit conditions, auto-recovering once the fault is cleared.
- Can the skip cycle level be adjusted in the NCP1377BD1R2G?
Yes, the skip cycle level can be adjusted, allowing the controller to enter burst mode at low power demand to avoid audible noise.
- What is the maximum junction temperature for the NCP1377BD1R2G?
The maximum junction temperature is 150°C.
- What is the storage temperature range for the NCP1377BD1R2G?
The storage temperature range is -60°C to 150°C.
- How does the NCP1377BD1R2G handle transformer core reset detection?
The IC uses an auxiliary winding for transformer core reset detection, ensuring discontinuous operation and providing overvoltage detection.
- Can external signals trigger the latch-off of the NCP1377BD1R2G?
Yes, external signals, such as from a temperature sensor, can trigger the latch-off of the IC.
