Overview
The NCP1377DR2G, 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 NCP1377DR2G 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 |
|---|---|---|---|---|
| Continuous Power Supply or Drive Voltage (VCC, Drv) | - | - | 18 | V |
| Transient Power Supply Voltage (Duration < 10 ms, IVCC < 20 mA) | - | - | 25 | V |
| Maximum Voltage on all other pins except Pin 8 (HV), Pin 6 (VCC) and Pin 5 (Drv) | -0.3 | - | 10 | V |
| Maximum Current into all pins except VCC (6), HV (8) and Demag (1) | - | - | 5.0 | mA |
| Maximum Junction Temperature (TJMAX) | - | - | 150 | °C |
| Temperature Shutdown | - | 155 | - | °C |
| Storage Temperature Range | -60 | - | 150 | °C |
| Output Voltage Rise-Time @ CL = 1.0 nF, 10-90% of Output Signal | - | 40 | - | ns |
| Output Voltage Fall-Time @ CL = 1.0 nF, 10-90% of Output Signal | - | 20 | - | ns |
| Source Resistance | 12 | 20 | 36 | Ω |
| Sink Resistance | 5.0 | 10 | 19 | Ω |
| Internal Current Setpoint | 0.9 | 1.0 | 1.1 | V |
| Sampling Delay After ON Time (NCP1377) | - | 4.5 | - | μs |
| OVP Internal Reference Level | 6.4 | 7.2 | 8.0 | V |
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): Detects overvoltage conditions and latches off the IC until the power supply is cycled down.
- Auto-Recovery Short-Circuit Protection via UVLO Crossover: Automatically recovers from short-circuit conditions by stopping switching pulses and restarting when 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: Adjusts the skip cycle level to optimize performance under varying load conditions.
- Internal 1.0 ms Soft-Start: Reduces startup stress and ensures a smooth startup sequence.
- Internal Temperature Shutdown: Protects the IC from overheating by shutting down at high temperatures.
- Transformer Core Reset Detection: Ensures discontinuous operation and provides fast OVP through an auxiliary winding.
Applications
The NCP1377DR2G is ideal for various applications, including:
- Low-Cost AC-DC Adapters: Efficient and reliable power conversion with minimal component count.
- Consumer Electronics: Suitable for power supplies in consumer devices due to its high-performance and low noise operation.
- Auxiliary Power Supplies: Used in auxiliary power supplies where reliability and efficiency are critical.
Q & A
- What is the primary function of the NCP1377DR2G?
The NCP1377DR2G is a PWM Current-Mode Controller designed for free-running quasi-resonant operation in AC-DC power supplies. - What are the key benefits of quasi-resonant operation in the NCP1377DR2G?
Quasi-resonant operation reduces EMI and video noise perturbations by restarting the MOSFET in the minimum of the drain-source wave. - How does the NCP1377DR2G handle overvoltage conditions?
The NCP1377DR2G features latched overvoltage protection, which detects overvoltage conditions and latches off the IC until the power supply is cycled down. - What is the purpose of the internal 1.0 ms soft-start in the NCP1377DR2G?
The internal 1.0 ms soft-start reduces startup stress and ensures a smooth startup sequence. - How does the NCP1377DR2G protect against short-circuit conditions?
The NCP1377DR2G automatically recovers from short-circuit conditions by stopping switching pulses and restarting when the fault is cleared through UVLO crossover. - What is the maximum junction temperature for the NCP1377DR2G?
The maximum junction temperature for the NCP1377DR2G is 150°C. - What are the storage temperature range limits for the NCP1377DR2G?
The storage temperature range for the NCP1377DR2G is from -60°C to 150°C. - How does the NCP1377DR2G handle temperature shutdown?
The NCP1377DR2G features internal temperature shutdown, which protects the IC from overheating by shutting down at high temperatures. - What is the role of the auxiliary winding in the NCP1377DR2G?
The auxiliary winding provides fast overvoltage protection and ensures discontinuous operation through transformer core reset detection. - What are some typical applications of the NCP1377DR2G?
The NCP1377DR2G is typically used in low-cost AC-DC adapters, consumer electronics, and auxiliary power supplies.
