LM2854MH-1000

LM2854MH-1000 Application Field and Working Principle

DC-DC switching regulators are typically used to convert one DC voltage to another either higher or lower voltage. LM2854MH-1000 is a fully integrated step-down switching regulator with a built-in high side switch which includes a 0.2Ω series driver in the same package. The regulator utilizes a fixed frequency, voltage-mode control. The device supports up to16V input voltage range and output current capability is from 3A to 4A maximum. It is designed to provide 12V output voltage with an external inductor and can be used in automotive and industrial applications.

Features

• Input voltage range: 2.8V to 16V
• 0.2Ω high side switch
• 3A to4A maximum output current capability
• External compensation
• Output voltage range: 0.8V to 12V
• Fixed frequency voltage-mode control
• Under voltage lockout
• Thermal shutdown

Application Fields

LM2854MH-1000 is widely used in automotive and commercial applications such as powering microprocessors and power solutions. Automotive market applications include VRMs, load switches, battery charging and battery-backed power supply systems. It suits applications where the power supply must meet wide input voltage and current needs and deliver high-power steady outputs. LM2854MH-1000 can also be used in industrial applications such as power over Ethernet (PoE), LED lighting, and industrial power tools.

Working Principle

LM2854MH-1000 operates in a fixed frequency voltage-mode control. It works by controlling the on-time of the switches and by modulating the duty cycle of the switching device. The duty cycle is determined by the external compensation, regulating the pulse width. With the duty cycle and frequency fixed, the required voltage is developed at the output and a linear regulation is maintained. The output voltage is dependent on the external components such as- inductor and capacitors.

The device utilizes two logic pins for an enable and for a power on reset which enables the circuit to shut down the switches and then releases the reset when V IN is above the defined threshold. To further protect the device, LM2854MH-1000 has features such as under voltage lockout and thermal shutdown, along with over current protection by virtue of the built-in high side switches. The device also provides a power-good signal indicating the output voltage is valid.