onsemi NCP1377DR2

The NCP1377DR2, 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 any load/line conditions. It features minimum drain voltage switching (quasi-resonant operation) and an inherent skip cycle capability, which allows the controller to enter burst mode when power demand falls below a predetermined level, eliminating audible noise at low peak current.

• Free-Running Borderline/Critical Mode Quasi-Resonant Operation: Ensures efficient operation with minimal primary switch turn-on losses and no secondary diode recovery losses.
• Latched Overvoltage Protection (OVP): The controller goes into a latched fault condition upon detecting an overvoltage, requiring a power cycle to reset.
• Auto-Recovery Short-Circuit Protection via UVLO Crossover: Automatically stops switching pulses and attempts to restart when the fault condition disappears.
• External Latch Triggering: Allows external signals, such as from a temperature sensor, to latch off the IC.
• Current-Mode with Adjustable Skip Cycle Capability: Enters burst mode at low power demand, reducing audible noise.
• Internal Temperature Shutdown: Protects the device from overheating.
• Transformer Core Reset Detection: Ensures borderline/critical operation under all conditions, easing feedback loop design).

The NCP1377DR2 is designed for various power management applications, including:

• Low-Cost AC-DC Adapters: Ideal for cost-sensitive designs requiring high performance and reliability).
• Consumer Electronics: Suitable for power supplies in consumer electronics due to its high-voltage technology and protective features).
• Auxiliary Supplies: Used in auxiliary power supplies where efficient and reliable operation is crucial).
• Switchmode Power Supplies (SMPS): Incorporates all necessary components for building rugged and reliable SMPS systems).

1. What is the primary function of the NCP1377DR2?

   The NCP1377DR2 is a PWM Current-Mode Controller designed for free-running quasi-resonant operation in switchmode power supplies (SMPS)).

2. What is the supply voltage range for the NCP1377DR2?

   The supply voltage range is 7.5 V to 18 V).

3. What is the switching frequency capability of the NCP1377DR2?

   The switching frequency can go up to 150 kHz for the NCP1377 and up to 300 kHz for the NCP1377B).

4. What type of topology does the NCP1377DR2 support?

   The NCP1377DR2 supports flyback topology).

5. What are the key protective features of the NCP1377DR2?

   The key protective features include current limiting, over temperature protection, over voltage protection, and auto-recovery short-circuit protection).

6. How does the NCP1377DR2 handle overvoltage conditions?

   The controller goes into a latched fault condition upon detecting an overvoltage, requiring a power cycle to reset).

7. What is the operating temperature range of the NCP1377DR2?

   The operating temperature range is -40°C to 125°C).

8. Does the NCP1377DR2 have an internal switch?

   No, the NCP1377DR2 does not have an internal switch).

9. What is the purpose of the soft-start feature in the NCP1377DR2?

   The soft-start feature eliminates traditional startup stress with an internal 1.0 ms soft-start time).

10. What are some common applications of the NCP1377DR2?

    Common applications include low-cost AC-DC adapters, consumer electronics, auxiliary supplies, and switchmode power supplies (SMPS)).