Overview
The NCP1623ASNT1G, produced by onsemi, is an enhanced, high-efficiency power factor correction (PFC) controller designed to optimize the efficiency of PFC stages across a wide load range. This controller is particularly suited for applications requiring high power factor, efficiency, and reliability. It operates in both critical conduction mode (CrM) and discontinuous conduction mode (DCM), ensuring high efficiency and stable operation under various load conditions.
Key Specifications
| Parameter | Symbol | Value | Units |
|---|---|---|---|
| Power Supply Input | VCC | −0.3 to 30 | V |
| CS/ZCD Pin with 5 mA of Clamp Current | CS/ZCD | −0.3 to 11.5 | V |
| Feedback Pin | FB | −0.3 to 9 | V |
| VCTRL Pin | VCTRL | −0.3 to 9 | V |
| Driver Voltage | DRV | −0.3 to 14 (internal clamp) | V |
| Error Amplifier Gain | GEA | 110 to 290 | μS |
| VCTRL Maximum Clamping Voltage | VCTRL(MAX) | 4.0 to 5.0 | V |
| VCTRL Minimum Clamping Voltage | VCTRL(MIN) | 0.3 to 0.8 | V |
| VCTRL Startup Source Current | IVCTRL(START) | 90 to 150 | μA |
Key Features
- Valley Synchronized Frequency Fold-back (VSFF): Operates in CrM until power drops below a threshold, then enters DCM with prolonged dead time, ensuring stable valley turn-on and high efficiency in both modes.
- On-time Modulation: Ensures near-unity power factor in both CrM and DCM operations.
- Follower Boost Capability (NCP1623A Only): Lowers output voltage regulation at low line conditions, enhancing efficiency and reducing inductor size.
- Skip Mode for Light Load Regulation: Optimizes efficiency at light loads.
- Sleep Mode with Low Current Consumption (SOIC8 Only): Reduces standby power.
- Fast Line / Load Transient Control: Includes dynamic response enhancer, soft OVP, and fast OVP for overshoot-less and undershoot-less output regulation.
- Excessive Current Protection: Features over current protection (OCP) and over stress protection (OVS).
- Brown Out Protection: Protects against low input voltage conditions.
- Thermal Shutdown (TSD): Disables the gate drive when the junction temperature exceeds 150°C.
- Disable Function (SOIC8 Package Only): Disables most internal blocks to minimize VCC supply current.
Applications
The NCP1623ASNT1G is ideal for systems requiring high power factor, efficiency, and reliability. Typical applications include:
- Power supplies for consumer electronics, such as smartphones, tablets, and notebooks.
- Universal AC input, constant voltage power supplies supporting PD3.0/PPS protocols.
- High-efficiency power supplies for industrial and medical devices.
- Systems where cost-effectiveness, compact design, and low standby power are essential.
Q & A
- What is the primary function of the NCP1623ASNT1G?
The NCP1623ASNT1G is a power factor correction (PFC) controller designed to optimize the efficiency of PFC stages in power supplies.
- In which modes does the NCP1623ASNT1G operate?
The controller operates in both critical conduction mode (CrM) and discontinuous conduction mode (DCM).
- What is Valley Synchronized Frequency Fold-back (VSFF)?
VSFF is a technique where the PFC stage operates in CrM until power drops below a threshold, then enters DCM with prolonged dead time, ensuring stable valley turn-on and high efficiency.
- How does the NCP1623ASNT1G handle light load conditions?
The controller features a skip mode for light load regulation and a sleep mode with low current consumption to optimize efficiency at light loads.
- What protection features are included in the NCP1623ASNT1G?
The controller includes over current protection (OCP), over stress protection (OVS), brown out protection, and thermal shutdown (TSD).
- How does the NCP1623ASNT1G manage transient conditions?
The controller features fast line/load transient control, including a dynamic response enhancer, soft OVP, and fast OVP for overshoot-less and undershoot-less output regulation.
- What is the significance of the VCTRL pin?
The VCTRL pin is the output of the error amplifier and is used to adjust the regulation loop bandwidth and provide a soft-start function at startup.
- How does the NCP1623A version differ from other versions?
The NCP1623A version includes a follower boost capability that lowers output voltage regulation at low line conditions, enhancing efficiency and reducing inductor size.
- What is the maximum operating voltage for the VCC pin?
The maximum operating voltage for the VCC pin is 30 V.
- What is the purpose of the DIS pin in the SOIC8 package?
The DIS pin in the SOIC8 package is used to disable most internal blocks, minimizing VCC supply current.
