NCP1937B2DR2G

Power Factor Correction (PFC) is a technology that is commonly used in electronic appliances such as computers and power supplies. Its goal is to improve the power factor of a system, and it does so by correcting the current waveform to match the voltage waveform. By improving the power factor, the system can deliver more power with the same amount of available power, resulting in greater efficiency and stability.

NCP1937B2DR2G is a PFC controller IC designed to provide a highly efficient and cost-effective solution for power factor correction (PFC). It is suitable for universal input voltage applications with high and low power factor applications. This device also offers a low standby power consumption and a high power factor of up to 97%.

The application fields of NCP1937B2DR2G are mainly in power supplies and switching power converters. It is ideal for designs that require a efficient, compact and cost-competitive PFC solution. This device features a proprietary POC event detection circuit, which helps reduce audible noise. The current mode control provides fast transient response and improved line and load regulation performance. The device also offers a wide range of protections, including overvoltage protection, overtemperature protection, overload protection.

The working principle of NCP1937B2DR2G is based on the current mode control of a buck converter, with a built-in PFC pre-regulator that controls the output voltage and provides dynamic power factor correction. The PFC pre-regulator is comprised of an active switch, a current source and a power transistor. The PFC pre-regulator operates in a discontinuous conduction mode (DCM) to control the output voltage. The controller monitors the output voltage, and adjusts the on-time of the active switch and the current source to control the output voltage.

The current source is a light-load control element, which limits the current flowing through the MOSFET. This element has two main parameters, duty factor and frequency, to control the current flow. The duty factor is determined by the PFC pre-regulator and the frequency is adjustable. The duty factor and frequency are proportional to the output voltage.

The power transistor is used to provide the output power. When the transistor is in saturation state, the voltage across it is zero and the peak current flowing through it is limited to a maximum level. In this state, the power switch is able to regulate the output power more accurately and efficiently.

In summary, NCP1937B2DR2G is an integrated high-efficiency PFC controller IC. Its application field is mainly found in power supplies and switching power converters. Its working principle is based on current mode control of a buck converter with a built-in PFC pre-regulator. The device features a proprietary POC event detection circuit, current source and power transistor, providing fast transient response, improved line and load regulation performance and wide range of protection.