Analog Devices / Maxim Integrated MAX77540 Dual-Phase Buck Converter

Analog Devices MAX77540 Dual-Phase Buck Converter is a high-efficiency step-down converter with two 3A switching phases. It uses an adaptive COT (constant on-time) current-mode control architecture, and the two 3A switching phases can be configured as either one (2Φ, 6A) or two (1Φ, 3A each) outputs. Its wide input voltage range directly converts sub-1V outputs from 3-cell Li+ batteries, USB PD, and 12VDC supply rails. The output voltages are preset with resistors and are further adjustable through an I2C-compatible interface. With 94% peak efficiency, low quiescent current, and compact solution size, the Analog Devices MAX77540 is ideal for battery-powered, space-constraint equipment.

Programmable switching frequency, frequency tracking, spread-spectrum, and ultrasonic mode allow easier system optimization for noise-sensitive applications. Dedicated EN, POK, and FPWMB pins provide options for direct hardware control, while more programmable options, such as soft-start/stop and ramp-up/down slew-rates, are available through I2C. An array of built-in protections ensures safe operation under abnormal operating conditions.


  • 4V to 16V input voltage range
  • 0.5V to 5.2V output voltage range
  • Resistor configurable default VOUT
  • Two 3A bucks (1Φ) or one 6A buck (2Φ)
  • ±0.5% VOUT accuracy (default VOUT at 25°C)
  • 94% peak efficiency (7.6VIN, 3.3VOUT, 1MHz)
  • Auto SKIP/PWM and low-power mode
  • 98% max. duty cycle dropout operation
  • Programmable soft-start/stop and ramp-up/down slew rates
  • Pre-biased startup and active output discharge
  • Programmable inductor peak current limits
  • 0.5/1.0/1.6MHz nominal switching frequency
  • Spread-spectrum modulation
  • Internal/external frequency tracking
  • Ultrasonic mode
  • Dedicated EN, POK, and FPWM pins
  • Undervoltage lockout (UVLO), thermal shutdown, and short-circuit protection
  • High-speed I2C I/F with 3-slave address options
  • 30-WLP (2.51mm x 2.31mm) and 24-FC2QFN (3mm x 3mm) packages
  • Less than 55mm2 total solution size


  • 2/3-Cell Li+ and USB-C™ Power Delivery systems
  • Microprocessors, field-programmable gate arrays (FPGAs), digital signal processors (DSPs), and application-specific integrated circuits (ASICs)
  • Audio and video equipment
  • Networking and PCIe®/redundant array of inexpensive disks (RAID) cards


Functional Block Diagram

Block Diagram - Analog Devices / Maxim Integrated MAX77540 Dual-Phase Buck Converter
Published: 2021-08-23 | Updated: 2023-04-18