ON Semiconductor SG3525M Pulse Width Modulator Controller

The SG3525M from ON Semiconductor is a versatile and high-performance pulse width modulator (PWM) controller designed for a wide range of power supply and motor control applications. This integrated circuit (IC) is engineered to provide all the necessary features to implement off-line or DC-to-DC fixed-frequency current-mode control schemes with minimal external components.

One of the key features of the SG3525M is its adjustable oscillator, which allows users to set the frequency of operation across a wide range. This flexibility makes it suitable for various applications, from low-frequency power inverters to high-frequency switching power supplies. The oscillator frequency can be adjusted through an external resistor and capacitor, giving designers the ability to tailor the device to their specific requirements.

The SG3525M also includes dual alternating outputs, which are designed to directly drive power MOSFETs or IGBTs in a push-pull configuration. This capability simplifies the design of high-efficiency power converters. Additionally, the outputs are capable of sinking and sourcing a high current, which ensures rapid charging and discharging of the gate capacitance of the power devices, leading to reduced switching losses.

Another significant feature of the SG3525M is its built-in under-voltage lockout circuit. This circuit ensures that the PWM controller only operates when the supply voltage is within an acceptable range, thus protecting the system from low-voltage conditions that could lead to inefficient operation or damage to the components.

The SG3525M also offers a range of protection features, such as a programmable soft-start function that limits the inrush current at startup, reducing stress on the power supply components. Additionally, the device has a shutdown pin that can be used to turn off the outputs, providing a simple method for implementing over-voltage or over-temperature protection circuits.

Overall, the SG3525M from ON Semiconductor is a reliable and versatile PWM controller that is an excellent choice for designers looking to optimize the performance and efficiency of their power supply and motor control systems.