LM25575MHX Datasheet/PDFThe LM25575MHX is a DC-DC switching regulator from the Pulse Width Modulation (PWM) controller family. It improves and simplifies the design of step-down, step-up and multiple output switching regulators. The device supports a constant-frequency, current mode PWM control architecture and is adjustable via an external resistor, allowing for adjustable output target frequency up to 1MHz and adjustable output voltage range from 0.8V to 90V. The LM25575MHX offers a wide range of applications in voltage regulator, integrated power stages, DC-DC converters, POL regulators, and VRMs.
Overview of Applications
The LM25575MHX is designed to serve as a DC-DC power-conversion building block, supporting multiple input and output voltages. It is suitable for a wide range of applications such as voltage regulators, integrated power stages, DC-DC converters, POL regulators, and VRMs. It can be used to achieve high-efficiency, low-noise, high-current, low-ripple operation.
Working Principle
The LM25575MHX uses a constant-frequency, current-mode PWM control architecture. Its key components include an error amplifier, PWM comparator, reference, and precision oscillator. The error amplifier compares the feedback input voltage to the internally generated reference voltage and generates an output voltage. The output voltage is then compared by the PWM comparator to the oscillator signal. If the voltage is higher than the oscillator signal, then the output switches ON and if it is lower than the oscillator signal, the output is switched OFF.
The LM25575MHX operates in one of the following three modes: continuous conduction mode (CCM), discontinuous conduction mode (DCM), and burst mode operation (BMO). In CCM, the inductor always carries current, while in DCM the inductor current goes to zero during each complete switching cycle and in BMO, the inductor current also drops to zero but the switch is operated at a PWM duty cycle. Depending upon the application, the best mode can be selected.
Advantages of LM25575MHX
The LM25575MHX offers a wide range of advantages such as excellent load and line regulation, high efficiency, low output noise, low quiescent current, fast transient response, and programmable features. The device features an adjustable output current limit, adjustable output voltage range, adjustable frequency, low quiescent current, and protection features such as current limit, temperature limit, and overvoltage protection.
The LM25575MHX also offers two operating modes that can be used to achieve superior efficiency and performance in various applications. The device supports pulse skipping operation to reduce the no-load quiescent current, as well as input current limit, which helps to reduce the input ripple current, further improving the device’s efficiency. The device also supports a diode emulation mode, which can be used to reduce input current and output voltage ripple.
Conclusion
The LM25575MHX is a versatile device that can be used for a wide range of applications in voltage regulators, integrated power stages, DC-DC converters, POL regulators, and VRMs. The device supports a range of adjustable features such as output target frequency, output voltage range, and adjustable output current limit that can be used to meet the demanding power requirements of the application. The device also supports two different operating modes that can be used to improve efficiency or performance. The LM25575MHX offers excellent load and line regulation, high efficiency, low output noise, low quiescent current, fast transient response, and programmable features.