1 Introduction

The LP8756x-Q1 and LP8752x-Q1 devices are designed to meet the power-management requirements of the latest processors and platforms in various automotive power applications. Both devices contain four stepdown DC/DC converter cores, which are configured as a 4-phase output, 3-phase and 1-phase outputs, 2-phase and 2-phase outputs, one 2-phase and two 1-phase outputs, or four 1-phase outputs. The devices are controlled by an I²C-compatible serial interface and by enable signals.

The automatic pulse-width-modulation (PWM) to pulsed-frequency-modulation (PFM) operation (AUTO mode) and the automatic phase adding and phase shedding maximizes efficiency over a wide output-current range. The LP8756x-Q1 and LP8752x-Q1 support remote differential-voltage sensing for multiphase outputs, which compensates the IR drop between the regulator output and the point-of-load (POL), improves the accuracy of the output voltage. The switching clock can be forced to the PWM mode and also synchronized to an external clock to minimize the disturbances.

LP8756x-Q1 and LP8752x-Q1 supports the load-current measurement without additional external current sense resistors. The devices also support programmable start-up and shutdown delays and sequences synchronized to enable signals. The sequences can include GPIO signals to control external regulators, load switches, and processor reset. During start-up and voltage change, the devices control the output slew rate to minimize an output voltage overshoot and in-rush current.

This application report can be used as a reference in selecting external components and phase configuration to achieve the wanted phase margin. This application report does not provide information about the electrical characteristics, package, or the functionality of the device. For this information and the full register maps, refer to LP8756x-Q1 16-A Buck Converter With Integrated Switches and LP8752x-Q1 10-A Buck Converter With Integrated Switches datasheets.