Use MAX5060 to design a high-current power supply with lossless current detection

Overview

Currently, most data processing units require greater current draw from the power supply to meet higher processing speeds. In these applications, non-destructive current detection and ground potential deviation are critical for accurate control of output voltage and output current.

The MAX5060 PWM step-down power supply controller uses average current mode control technology to track load current, and the device uses differential detection technology to accurately control the output voltage. In this reference design, the equivalent series resistance (DCR) of the inductor is used to detect the current, eliminating the power consumption of the current-sense resistor.

This reference design provides a high current (30A) power supply design solution with high system efficiency and good load regulation. The complete circuit schematic, bill of materials (BOM), efficiency measurement and test results are given below.

Specifications and design steps

• The reference design is capable of meeting the following specifications.

• Input voltage: 12V ±10%

• Output voltage: 1.5V

• Output current: 30A

• Output ripple: ±15mV

• Input ripple: ±250mV

• Efficiency: >88% at half full load (15A)

• Switching frequency: 275kHz

• Circuit board dimensions: 5cm × 3.3cm

The reference design schematic is shown in Figure 1, and the component list is shown in Table 1. The MAX5060 uses a buck configuration in the design.

Detailed Image (PDF, 100kB)
Figure 1. MAX5060 Buck Converter Schematic (F _SW = 275kHz)