MP38891DL-LF-P

MP38891DL-LF-P Application Field and Working Principle

The MP38891DL-LF-P is one of Monolithic Power System’s range of DC/DC switching regulators, which offer a wide range of voltage regulation and conversion options. This product is a synchronous buck regulator with a 1A output current and an input voltage range of 4.0V to 25V. It is targeted towards point-of-load (POL) applications in the computers, networking, and communication infrastructure markets.

The MP38891DL-LF-P is a single-output device designed as a step-down regulator, also known as a “buck” regulator. It receives energy directly from the input voltage source, regulates the voltage and then passes it to the load circuit. It has a maximum output current of 1A and efficiency up to 94%. One of the advantages of the MP38891DL-LF-P is its low quiescent current of 2mA, which makes it ideal for low-power or battery-powered applications.

Working Principle

The main function of a DC/DC switching regulator is to convert the input voltage to an output voltage, which is significantly lower than the input voltage. It does this by switching an inductor in a current-controlled mode. The inductor forms a part of a resonant tank comprising a capacitor and a resistor. As the current through the inductor increases, the inductance reduces and the current is limited. This phenomenon is known as current limiting.

When the voltage across the inductor reaches its peak, the MOSFET switches off and the resonant tank is free to discharge into the output. The output voltage is determined by the resistive voltage divider, which is made up of two resistors connected in series. The ratio of the two resistors determines the output voltage. The whole process works in such a way that the output is DC regulated voltage irrespective of the changes in the input voltage.

The MOSFET is the main component in a switching regulator that switches the current on and off. It is commonly used with a Schottky diode to control the current flow. The diode prevents the current flowing back into the inductor when the MOSFET switches off, thus allowing the resonant tank to discharge into the output.

Features and Benefits

The MP38891DL-LF-P is a single-output voltage regulator featuring a 1A output current and an input voltage range of 4.0V to 25V. It has a high switching frequency of up to 2MHz and a low quiescent current of only 2mA. This device is designed for high-efficiency buck regulators, with efficiency up to 94%. This device supports a synchronous rectification architecture. It has a programmable soft-start feature, which reduces inrush current during start-up.

The device has built-in protection features to protect against faults, such as overvoltage and over current protection. It also has an output disconnect feature, which enables the user to disconnect the output voltage without having to physically remove the voltage regulator from the circuit. In addition, the device features a power-good output to indicate the condition of the output voltage.

The MP38891DL-LF-P is designed specifically for high-performance point-of-load applications. It is a cost-effective evaluation board for power engineers to utilize for complete design verification of their POL designs. Monolithic Power Systems offers complete software and hardware support for the MP38891DL-LF-P, along with an application note and reference design.