ON Semiconductor MC33368D High Voltage Switching Regulator

The MC33368D from ON Semiconductor is a versatile and high-performance switching regulator designed for AC-DC converters and off-line fixed frequency, current-mode switched-mode power supplies. This integrated circuit (IC) offers a plethora of features that make it an excellent choice for a wide range of applications requiring efficient power conversion.

One of the key features of the MC33368D is its high voltage capability, which allows it to directly interface with the rectified mains voltage, eliminating the need for a separate step-down transformer. This not only simplifies the design but also enhances the overall efficiency of the power supply. The device operates at a fixed frequency, which can be set by the user, ensuring predictable performance and easy noise filtering.

The MC33368D integrates a range of protection features to ensure safe operation under various conditions. It includes an overvoltage protection circuit that guards the system against transient voltage spikes. Additionally, the under-voltage lockout (UVLO) function ensures that the IC operates only when the input voltage is within an acceptable range, thus preventing malfunctions due to low input voltages.

Another notable feature of the MC33368D is its current-mode control, which provides excellent line and load regulation, as well as a faster transient response compared to voltage-mode control. This feature, combined with the internal error amplifier, allows for precise output voltage regulation, which is critical in applications where a stable power supply is paramount.

Thermal shutdown is also incorporated into the MC33368D to protect the IC from overheating. In the event of excessive temperature, the thermal shutdown circuitry will turn off the device, thus preventing thermal runaway and potential damage to the IC and the system it powers.

Overall, the MC33368D is a robust and reliable solution for power supply designs that require high efficiency, compact size, and comprehensive protection features. Its ability to handle high voltages and its user-friendly interface make it an ideal choice for designers looking to create sophisticated power systems with minimal external components.