LM2574N-005

The LM2574N-005, manufactured by Texas Instruments, is a high-efficiency, monolithic step-down DC-DC switching regulator. It offers a high output current of 3A from a wide input voltage range of 4.1V to 75V. This device enables a cost-effective alternative to linear regulators with up to 90% conversion efficiency. The high switching frequency ensures low noise and minimized components size, while the low quiescent current of 3mA reduces the amount of waste heat and extends battery life in battery-powered applications. All of these features make the LM2574N-005 a great choice for designers, who need a reliable and versatile power solution.

Application Fields

The LM2574N-005 can be used in a wide variety of applications. It is commonly used as a power source in portable audio and video equipment, notebook and laptop computers, desktop computers, DSL modems, LCD televisions and monitors, network switches, and other electronic devices. Furthermore, its low quiescent current and wide input voltage range enable the LM2574N-005 to be used as a power supply for communication systems, automotive systems, medical systems and other low-power applications.

Working Principle

The LM2574N-005 is a monolithic step-down DC-DC switching regulator. It incorporates an internal high-side N-channel MOSFET switch, an internal PNP Darlington transistor, a low-side N-channel MOSFET switch, a voltage reference, and an error amplifier. An external resistor-capacitor (R-C) network determines the switching frequency and the peak current limit while an external inductor is used to store energy during switch cycles. The output voltage is determined by an external resistor divider, which provides a feedback voltage to the regulator.

The operation starts with a “Startup Voltage” (VSTART) that is sent to the error amplifier, which is compared to the reference voltage (VREF), the “FB” reference of the error amplifier is used to control the switching time. Each time the error amplifier output voltage goes beyond the reference voltage, the internal switch turns off. This turns on the PNP Darlington transistor and the internal N-channel MOSFET switch, and connects the output to the inductor. As the regulator goes through a number of switching cycles, the regulator reduces the output voltage until it reaches its regulation voltage. This regulation voltage is set with the help of an external resistor-capacitor network that acts as the feedback loop.

Conclusion

The LM2574N-005 is a high-efficiency monolithic step-down DC-DC switching regulator. It has a wide input voltage range of 4.1V to 75V and offers a high output current of 3A. The device is used in a range of applications such as portable audio and video equipment, notebook and laptop computers, desktop computers, DSL modems, LCD televisions and monitors, network switches, and other electronic devices. The regulator\'s low quiescent current and wide input voltage range make it suitable for a variety of low-power applications. The device operates by using a Startup Voltage (VSTART) and an R-C network to set the switching frequency, peak current limit, and output voltage. This helps ensure efficient, reliable, and cost-effective power supply solutions.