LM2698EVAL

The LM2698EVAL is an evaluation board for the LM2698 Switched Mode Power Supply (SMPS) circuit. This device was designed by Texas Instruments to provide a low cost and highly efficient alternative to traditional linear power supplies.

It uses a unique switching topology that permits the supply of both DC and AC power to various loads. The device\'s design provides flexibility, allowing it to be used in a wide variety of applications. The LM2698EVAL is primarily used in applications where low power supply loss is desired and only a small amount of space is available, such as battery-powered products or power supplies for low-power light systems.

The LM2698EVAL has four external components: a diode bridge, an inductor, a capacitor and a resistor. These components form the necessary circuit components for the switchmode power conversion, and should be selected with care in order to achieve the desired design performance. The LM2698EVAL operates with an input voltage of 8–36V and is able to deliver a high peak output current of up to 150mA.

The working principle behind the LM2698EVAL is based on the flyback topology, which is the most common topology used in switching power supplies. It consists of an inductor coupled to the input of the power supply, a storage capacitor for energy storage, and a diode bridge rectifier to convert alternating current (AC) to direct current (DC).

The main operation of the LM2698EVAL relies on two connected capacitors, known as the bootstrap and the synchronous-rectified capacitors, to variously switch the energy stored in the inductor over to the output. This technique is known as synchronous rectification, and allows for the transfer of energy from a switching power supply while minimizing losses due to high frequency switching.

The energy stored in the inductor is then transferred through the diode bridge, the storage capacitor, and the synchronous rectification capacitor to the output. The LM2698EVAL also includes protection features to ensure the safe operation of the device, such as a soft start pin that limits the inrush current and a current limit pin to protect the device from an over current situation.

In conclusion, the LM2698EVAL is a highly efficient and low cost evaluation board for use in applications that require both DC and AC power. It utilizes a flyback topology for the switching power conversion, and its four external components should be carefully selected to achieve the desired performance. The LM2698EVAL also includes various protection features, such as a soft start pin and a current limit pin, to ensure safe operation.