Overview
The NCP1377BPG, produced by onsemi, is a PWM Current-Mode Controller designed for free-running quasi-resonant operation. This controller combines a true current mode modulator with a demagnetization detector, ensuring full borderline/critical conduction mode in various load and line conditions. It is particularly suited for applications where low part count and high performance are crucial, such as in low-cost AC-DC adapters, consumer electronics, and auxiliary power supplies.
Key Specifications
| Characteristic | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 7.5 | - | 18 | V |
| Maximum Junction Temperature (TJMAX) | - | - | 150 | °C |
| Temperature Shutdown | - | - | 155 | °C |
| Storage Temperature Range | -60 | - | 150 | °C |
| ESD Capability (HBM Model) | - | - | 2.0 kV | - |
| Output Voltage Rise-Time @ CL = 1.0 nF | 40 | - | - | ns |
| Output Voltage Fall-Time @ CL = 1.0 nF | 20 | - | - | ns |
| Internal Timer Duration (NCP1377B) | - | - | 3.0 μs | - |
| 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): Protects against overvoltage conditions by latching 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 entering a safe low-power mode.
- External Latch Triggering: Allows external signals, such as from a temperature sensor, to latch off the IC.
- Current-Mode with Adjustable Skip Cycle Capability: Enables noise-free operation by adjusting the skip cycle level to occur only at low peak current.
- 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 borderline/critical operation and minimizes primary switch turn-on losses and secondary diode recovery losses.
Applications
The NCP1377BPG 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 NCP1377BPG?
The NCP1377BPG is a PWM Current-Mode Controller designed for free-running quasi-resonant operation in switchmode power supplies.
- What is the significance of the demagnetization detector in the NCP1377BPG?
The demagnetization detector ensures full borderline/critical conduction mode, minimizing primary switch turn-on losses and secondary diode recovery losses.
- How does the NCP1377BPG handle overvoltage conditions?
The NCP1377BPG features latched overvoltage protection, which latches off the IC until the power supply is cycled down to a safe voltage level.
- 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 NCP1377BPG protect against short-circuit conditions?
The device stops pulses and enters a safe low-power mode when a short-circuit condition is detected, and it auto-recovers once the fault is cleared.
- Can the NCP1377BPG be triggered externally to latch off?
Yes, the NCP1377BPG allows external signals, such as from a temperature sensor, to latch off the IC.
- What is the maximum junction temperature for the NCP1377BPG?
The maximum junction temperature is 150°C.
- What is the storage temperature range for the NCP1377BPG?
The storage temperature range is from -60°C to 150°C.
- What type of ESD protection does the NCP1377BPG have?
The NCP1377BPG has an ESD capability of 2.0 kV according to the HBM model.
- What are some common applications for the NCP1377BPG?
Common applications include low-cost AC-DC adapters, consumer electronics, auxiliary power supplies, and switchmode power supplies (SMPS).
