Overview
The NCP1377PG, manufactured 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 NCP1377PG 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 component count.
Key Specifications
| Characteristic | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 7.5 | 11 | 18 | V |
| High-Voltage Pin (HV) | - | - | 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 Junction Temperature | - | - | 150 | °C |
| Storage Temperature Range | -60 | - | 150 | °C |
| ESD Capability (HBM Model) | - | - | 2.0 kV | - |
| Internal Soft-Start Time | - | 1.0 | - | ms |
Key Features
- Free-Running Borderline/Critical Mode Quasi-Resonant Operation: Ensures efficient operation with minimal drain voltage switching.
- 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 pulses and attempting to restart.
- Current-Mode with Adjustable Skip Cycle Capability: Allows for noise-free operation by adjusting the skip cycle level.
- Internal 1.0 ms Soft-Start: Reduces startup stress and ensures a smooth startup sequence.
- Internal Temperature Shutdown: Protects the device from overheating.
- External Latch Triggering: Allows external signals, such as from a temperature sensor, to latch off the IC.
- Transformer Core Reset Detection: Ensures borderline/critical operation and minimizes primary switch turn-on losses and secondary diode recovery losses.
Applications
The NCP1377PG is ideal for various applications, including:
- Low-cost AC-DC adapters
- Consumer electronics
- Auxiliary power supplies
- Switchmode Power Supplies (SMPS)
Q & A
- What is the primary function of the NCP1377PG?
The NCP1377PG is a PWM Current-Mode Controller designed for free-running quasi-resonant operation in switchmode power supplies.
- What are the key benefits of quasi-resonant operation in the NCP1377PG?
Quasi-resonant operation reduces EMI and video noise perturbations by restarting the MOSFET in the minimum of the drain-source wave.
- How does the NCP1377PG handle overvoltage conditions?
The NCP1377PG 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 soft-start feature?
The internal 1.0 ms soft-start reduces startup stress and ensures a smooth startup sequence.
- How does the NCP1377PG protect against short-circuit conditions?
The NCP1377PG automatically recovers from short-circuit conditions by stopping pulses and attempting to restart through UVLO crossover.
- Can the skip cycle level be adjusted in the NCP1377PG?
Yes, the skip cycle level can be adjusted to ensure noise-free operation at low peak current.
- What is the maximum junction temperature for the NCP1377PG?
The maximum junction temperature is 150°C.
- How does the NCP1377PG handle temperature shutdown?
The device features internal temperature shutdown to protect against overheating.
- Can external signals latch off the NCP1377PG?
Yes, external signals, such as from a temperature sensor, can latch off the IC.
- What are the typical applications for the NCP1377PG?
The NCP1377PG is typically used in low-cost AC-DC adapters, consumer electronics, auxiliary power supplies, and switchmode power supplies.
