MAXREFDES179# Reference Design Board

The MAXREFDES179 reference design board is a standalone 45W USB type-C PD fast-charger, fuel-gauge, and protection solution for 2S Li+ batteries. It also provides 8A output at a voltage of 1S very efficiently to power systems with power management integrated circuits (PMICs) designed for 1S voltages.

The MAXREFDES179 allows the easy evaluation of the USB-C PD controller, buck-boost charger, fuel gauge with integrated protection, and 2S-to-1S switched-capacitor converter.

The MAX77958 is a complete solution to detect the USB type-C CC and implement the PD protocol. The MAX77960 is a 45W wide-input buck-boost charger with integrated field-effect transistors (FETs) for 2S Li+ batteries. The MAX77932 is a dual-phase switched-capacitor converter with integrated power switches that delivers 8A output current and divides the input voltage by two. The MAX77932 also simplifies the migration by converting the 2S battery voltage to 1S-equivalent output and preserves the existing downstream 1S power architecture. The MAX17320 is a fuel-gauge IC with a protector and SHA-256 authentication for two to four series lithium-ion/polymer batteries. The fuel gauge uses the ModelGauge m5 algorithm that automatically compensates for cell aging, temperature, and discharge rate, and provides accurate state-of-charge (SOC) in milliampere-hours (mAh) or percentage (%) over a wide range of operating conditions to protect the battery.

The graphical user interface (GUI) is Windows-based. A register-based interface exercises the features of the MAX77932, MAX77958, MAX77960, and MAX17320.

The design files, firmware, and software are available in the Design Resources tab. The board is also available for purchase.


  • Input operating range of 3.5V to 25V
  • Type-C and USB-PD support
    • DRP and Try,Snk state
    • Cable orientation, power role detection
    • Integrated VCONN switch with OCP
  • Autonegotiate for the highest PD power profile (45W) when Sink
  • Autoenable OTG when Source
  • Autoconfigurable battery charger
  • AP control to overwrite PD power profile, OTG limit, USB-PD functions, buck-boost charger configuration, read/write MAX17320 fuel gauge status, configure MAX77932 switched capacitor converter


  • Smartphones, tablets
  • Cameras
  • Gaming consoles
  • Medical devices
  • Power banks
  • Industrial equipment
MAXREFDES179# System Board Enlarge+

MAXREFDES179# Block Diagram Enlarge+

Required Equipment

  • MAXREFDES179 reference design board package (Figure 2)
    • MAXREFDES179 reference design board and Micro-B USB cable
    • MAXREFDES179 Battery Power and MAXREFDES179 Battery Fuel Gauge software (GUI)
  • Oscilloscope
  • Battery simulator
  • Voltage and current multimeters
  • USB-C PD power adapter (USB compliant) and USB-C to on-the-go (OTG) cable
  • PC with Windows 10 operating system

Buy the Reference Design
Buy direct: MAXREFDES179
Order the reference design MAXREFDES179 from your local Maxim representative.


25VIN 3A/6AOUT USB-C Buck-Boost Charger with Integrated FETs for 2S/3S Li-Ion Batteries

  • 3.5V to 25.4V Input Operating Range, 30VDC Withstand
  • 97% Peak Efficiency for 2S Battery at 9VIN/7.4VOUT/1.5AOUT
  • 97% Peak Efficiency for 3S Battery at 15VIN/12.6VOUT/2AOUT

2S-4S ModelGauge m5 EZ Fuel Gauge with Protector, Internal Self-Discharge Detection, and SHA-256 Authentication

  • Battery Health + Programmable Safety/Protection
  • ModelGauge m5 EZ Algorithm
  • Precision Measurement Without Calibration

Standalone USB Type-C and USB Power Delivery Controller

  • Customizable Firmware
  • USB Type-C Support and USB-PD Support
  • Supports BC1.2 Legacy/Proprietary Charger Detection
  • WLP 6x5 Bumps 0.5mm Pitch Package