MAX5035BUSA

Introduction

MAX5035BUSA is a non-synchronous upgraded version of the conventional DC-DC switching regulator. It is a current mode, step-down controller capable of providing up to 1.2A of output current. Its high frequency enables a smaller inductor and capacitor design which makes it an ideal solution for space-constrained applications. The MAX5035BUSA provides an adjustable output voltage from 0.8V to 5.5V with an input voltage range of 2.7V to 5.5V and an internal 3% reference voltage accuracy. It features internal compensation, current-mode operation, frequency foldback and programmable soft-start.

Application Field

The MAX5035BUSA is well suited for application in handheld and portable system such as mobile phones and digital cameras. It can also be used in numerous power management applications such as LCD displays in netbooks, desktop PCs and LCD TVs. Furthermore, it can be used in embedded systems such as industrial, medical equipment and consumer electronics.

Working Principle

The primary output regulator of the MAX5035BUSA is based on a buck topology. It uses an internal power MOSFET for switching. The internal current sensing element senses the current flowing across the MOSFET and enables precise regulation of the output voltage. The sense-element voltage is compared to the reference voltage and the error signal generated is the input to the internal PWM comparator. When the sensed voltage is greater than the reference voltage the output of the comparator is low, turning off the power MOSFET. If the sensed voltage is lower than the reference voltage, the comparator output is high, turning on the power MOSFET. The output voltage is regulated to a value determined by the feedback pin, which is compared to the internal reference voltage.

The MAX5035BUSA also features an adjustable switching frequency up to 1.5MHz. The higher switching frequency allows for reduced external component size and more flexibility in designs. As the output current increases, the voltage across the MOSFET increases and the current increases linearly with the output current. The MAX5035BUSA also features frequency foldback to maintain the peak current. Frequency foldback reduces the switching frequency as the load current increases to keep the peak current below the maximum value.

Conclusion

The MAX5035BUSA is a versatile, high-performance buck DC-DC controller designed for a wide range of space- and power-constrained applications. It features an adjustable switching frequency up to 1.5MHz, frequency foldback, programmable soft-start and current-mode operation for high performance and line/load regulation. It is well suited for applications in mobile phones, digital cameras, embedded systems, LCD displays and a variety of other portable and power management applications.