Top

MAXREFDES179# Reference Design Board

MAXREFDES179

Reference Design Disclaimer See the  Important Notice and Disclaimer  covering reference designs and other Maxim resources.

Description

The MAXREFDES179 reference design board is a standalone 27W 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 27W 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.

Features

  • 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

  • maxrefdes179fig02

    maxrefdes179fig02

  • MAXREFDES179

    MAXREFDES179

Icon

Designed, Built, Tested

Board pictured here has been fully assembled and tested.

 

Details Section

Details Section

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

 

Procedure

Figure 1. MAXREFDES179# System Board Figure 2. MAXREFDES179# Block Diagram

The reference design board is fully assembled and tested. Follow the steps to verify the board operation:

  1. Identify the connections and test points (Figure 1). Confirm all the shunts and jumpers are at their default positions (Table 1).
  2. Install the MAXREFDES179 Battery Power and MAXREFDES179 Battery Fuel Gauge software (GUI) on the PC.
  3. Connect the Micro-B USB cable from the PC to the MAXREFDES179 reference design board. The Light-Emitting Diodes (LEDs) light up. Figure 3 shows the driver is installed properly.
  4. Set up the test circuit (Figure 4). Preset the battery simulator to 7.4V and current limit to 100mA.
  5. Toggle SW2 to wake the MAX17320 fuel gauge (needed only to power cycle the board).
  6. Ensure the battery sourcing current is low (<100mA). Then only increase the current limit to 3.5A.
  7. Start the MAXREFDES179 Battery Power GUI and click Connect. A pop-up message indicates the successful connection (Figure 5). Proceed with Read and Close.
  8. Start the MAXREFDES179 Battery Fuel Gauge GUI. It automatically connects to the reference design.
  9. Read the status of the USBC, charger, 2S to 1S battery voltage conversion, and fuel gauge.
    1. MAX77958 USBC tab → Interrupts, Status, Command (Figure 6 and Figure 7).
    2. MAX77960 Charger tab → Interrupts/Status, Configurations (Figure 8 and Figure 9).
    3. MAX77932 tab → Status, Configurations (Figure 10 and Figure 11).
    4. MAXREFDES179 Battery Fuel Gauge → ModelGauge m5, protector, graphs, etc. (Figure 12)
  10. The reference design completes its initialization. The VBUS, VSYS, and I2C pull up. The CC pin waveforms can be monitored using the oscilloscope (Figure 13).

Safely remove hardwareFigure 3. Safely remove hardware.

Quick start connection diagramFigure 4. Quick start connection diagram.

MAXREFDES179 Battery Power GUI connectionFigure 5. MAXREFDES179 Battery Power GUI connection.

USB-C statusFigure 6. USB-C status.

USB-C interruptsFigure 7. USB-C interrupts.

Charger interrupts_statusFigure 8. Charger interrupts_status.

Charger configurationsFigure 9. Charger configurations.

MAX77932 statusFigure 10. MAX77932 status.

MAX77932 configurationsFigure 11. MAX77932 configurations.

MAXREFDES179 Battery Fuel Gauge GUIFigure 12. MAXREFDES179 Battery Fuel Gauge GUI.

Waveform after initializationFigure 13. Waveform after initialization.

Detailed Description of the Hardware and Software

Software (GUI and Drivers)

  • Contact the respective Maxim representative to download the GUI.
  • The Future Technology Devices International (FTDI) drivers installation guide is available on the FTDI webpage (https://www.ftdichip.com/Drivers/VCP.htm).

Switched-Capacitor Converter, Fuel Gauge, Charger, and USB-C Measurement Points
The reference design board has various test points to evaluate the performances of the switched-capacitor converter (MAX77932), fuel gauge (MAX17320), buck-boost charger (MAX77960), and USB-C PD (MAX77958). Table 2. Test points. summarizes the recommended test points.

Table 1. Default shunt positions and jumper descriptions (MAX77932, MAX17320, MAX77960, and MAX77958 configurations).

USB-C Default Position Function
J9 Pin 1-2 VCIN supply to MAX77958
J32 Open GPIO6 = pull down 330k to GND, MAX77958 slave address 0x27'h
J40 Open GPIO6 = pull up 330k to VIO1, MAX77958 slave address 0x26'h
J41 Pin 1-2 GPIO6 = GND, MAX77958 slave address 0x25'h
J15 Pin 1-2 Connect VBUS to DCIN
J16 Pin 1-2 Connect SYS to MAX77958
J21 Pin 1-2 Connect MAX77958's SCL_M to MAX77960
J22 Pin 1-2 Connect MAX77958's SDA_M to MAX77960
J20 Pin 1-2 MAX77960's INTB to MAX77958's GPIO8
J19 Open 3.3V supply to VIO2
J33 Pin 1-2 1.8V supply to VIO2
J34 Pin 1-2 1.8V supply to VIO1
J35 Pin 1-3 MAX77958's GPIO2 to enable/disable VCIN supply
Charger Default Position Function
J5 Pin 2-3 OTG = I2C control
J3 Pin 2-3 QBAT = I2C control
J7 Pin 2-3 STBY = I2C control
J13 Pin 1-2 Connect THM to 10k thermistor pull down to GND to indicate battery is connected and temperature is normal.
Fuel Gauge Default Position Function
J43 Pin 1-2 Connect MAX17320's INTB to FTDI 1
J44 Pin 1-2 Connect MAX17320's SDA to FTDI 1
J46 Pin 1-2 Connect MAX17320's SCL to FTDI 1
J38 Pin 1-2 2 CELLS configuration
J39 Pin 1-2 2 CELLS configuration
J4 Pin 5-6 402Ω to ZVC pin
Switched-Capacitor Converter Default Position Function
J6 Pin 1-2 1.8V supply to VIO
J36 Pin 1-2 Connect MAX77932's INT to FTDI 1
J37 Pin 1-2 Connect MAX77932's SDA to FTDI 1
J42 Pin 1-2 Connect MAX77932's SCL to FTDI 1
J26 Pin 1-2 SCC PGOOD indicator
J30 Pin 1-2 EN of SCC
J31 Open NC
FTDI Default Position Function
J18 Open Connect VOUT_5V to input LDOs
J2 Pin 1-2 PVL to pull up I2C Bus
J27 Pin 1-2 FTDI 1's SCL_FT
J29 Pin 1-2 FTDI 1's SDA_FT
J28 Pin 1-2 FTDI 1's INTB_FT
J45 Pin 2-3 PVL to pull up I2C Bus

Table 2. Test points.

Configuration Test Points Description
MAX77958 + MAX77960 + MAX17320 CC1, CC2
SCL_FT, SDA_FT SCL_M, SDA_M
DCIN/GND5
SYS/PGND2
BATTP/BATTN
USB-C signals
I2C Bus to MAX77958
I2C Bus to MAX77960
Charger Input Voltage/VBUS
Charger Output Voltage
BATT Input (2 Cells ~7.4V)
MAX77932 OUT/PGND1
SYS/PGND2
VIO
EN
PGOOD
Output Voltage
Input Voltage
VIO Input Voltage
Enable Pin
Power Good Pin

Demo 1: Switched-Capacitor Converter (MAX77932) Power Up/Down
Figure 14 shows the MAXREFDES179 reference design board setup to power-up/down the MAX77932.

  1. Enable and disable MAX77932 by the EN pin (Figure 15).
  2. Enable and disable MAX77932 by the I2C configuration (Figure 16).
  3. Enable MAX77932 by the EN pin and disable MAX77932 by the VIO signal (Figure 17).

MAXREFDES179 reference design board setupFigure 14. MAXREFDES179 reference design board setup.

Enable and disable MAX77932 by the EN pinFigure 15. Enable and disable MAX77932 by the EN pin.

Enable and disable MAX77932 by the I2C configurationFigure 16. Enable and disable MAX77932 by the I2C configuration.

Enable MAX77932 by the EN pin and disable MAX77932 by the VIO signalFigure 17. Enable MAX77932 by the EN pin and disable MAX77932 by the VIO signal.

Demo 2: Power Adapter is Connected When in Battery Mode
Figure 18 shows that the MAXREFDES179 reference design board setup supports autonegotiate for the highest PD power profile. Any USB-C PD adapter between 15W to 100W can be plugged in. The default highest PD power profile is 45W (15V/3A). Follow the steps to read the status:

  1. Figure 19 shows the VBUS waveform when the power adapter is connected.
  2. Read the USBC Status and observe the VBUS analog-to-digital converter (ADC) changes (Figure 20).
  3. Read the current SrcCap, charger configuration, and status (Figure 21 and Figure 22).
  4. Figure 23 shows the battery charging voltage and current.

Enable MAX77932 by the EN pin and disable MAX77932 by the VIO signalFigure 18. Enable MAX77932 by the EN pin and disable MAX77932 by the VIO signal.

Autonegotiate for the highest PD power profileFigure 19. Autonegotiate for the highest PD power profile.

VBUS ADC statusFigure 20. VBUS ADC status.

Current SrcCap (0x30) indicates negotiated PD power profileFigure 21. Current SrcCap (0x30) indicates negotiated PD power profile.

Charger configurations and detailsFigure 22. Charger configurations and details.

Battery charging voltage and current shown in the fuel gauge (MAX17320) GUIFigure 23. Battery charging voltage and current shown in the fuel gauge (MAX17320) GUI.

Demo 3: Manual Negotiation for a Different PD Profile
The MAXREFDES179 reference design board is user-programmable to negotiate for a different PD profile. Follow the steps to program to the other PD profile:

  • Battery Mode Setup - Plug in the USB-C PD power adapter (USB compliant) and connect the GUI (Figure 24).
  • Go to the Command tab → Select Current SrcCap (0x30) and click Write to read the selected PDO and current source capabilities of the far-end device. For example, the negotiated highest PD power profile is 15V, 3A (Figure 25).
  • Fill the SrcCap request and click Write to request for a different source capability. For example, request for PDO2 (9V, 3A) as the new PD power profile (Figure 26).
  • The VBUS changes from 15V to 9V (Figure 27).
  • Read the newly selected PDO in the Current SrcCap (0x30) and USB status (Figure 28).

    Battery charging voltage and current shown in the fuel gauge (MAX17320) GUIFigure 24. Manual negotiation for a different PD profile battery-mode setup.

    USB-C command - current SrcCap before negotiating for a different PD profileFigure 25. USB-C command - current SrcCap before negotiating for a different PD profile.

    USB-C command - current SrcCap before negotiating for a different PD profileFigure 26. USB-C command - SrcCap request for PDO2 (9V,3A).

    VBUS changes from 15V to 9VFigure 27. VBUS changes from 15V to 9V.

    Current SrcCap and USB-C status after a new PD power profile is establishedFigure 28. Current SrcCap and USB-C status after a new PD power profile is established.

    Demo 4: Sink (PPS) with GUI Control
    The MAXREFDES179 reference design board is user-programmable to negotiate for a different PD profile. Follow the steps to program to the other PD profile:

    1. Battery Mode Setup - Insert a 25W USB-C PD power adapter (PPS) and connect the GUI (Figure 29).
    2. The AP has full control to achieve the best battery-charging efficiency by optimizing (increase/decrease) the VBUS voltage and current level.
    3. MAXREFDES179 Battery Power GUI → Tools → Run Scripts → Select Scripts PPS_5V_to_11V_to_5V_2.25A → Execute. The scripts demonstrate that the PPS function is enabled and request a new APDO (+500mV per second) from 5V to 11V. The scripts request a new APDO (-500mV per second) from 11V to 5V once the VBUS reaches 11V (Figure 30).

    Insert the USB-C PD power adapter with the PPS featuresFigure 29. Insert the USB-C PD power adapter with the PPS features.

    AP requests new VBUS level (500mV) every second to demonstrate the PPS featuresFigure 30. AP requests new VBUS level (500mV) every second to demonstrate the PPS features.

    Demo 5: OTG Mode
    The MAXREFDES179 reference design board supports the OTG mode autonomously. Follow the steps to read the OTG status:

    1. OTG mode setup - Ensure the battery simulator is connected to the BATTP and BATTN pins. The GUI reads the register status. Plug in the OTG cable/device (Figure 31).
    2. The VBUS is enabled during the OTG mode (Figure 32).
    3. Read the USBC Status and observe the VBUS ADC (Figure 33).
    4. Read the charger configuration (Figure 34 and Figure 35).

    OTG mode setupFigure 31. OTG mode setup.

    VBUS during the OTG modeFigure 32. VBUS during the OTG mode.

    USB-C status is enabled during the OTG modeFigure 33. USB-C status is enabled during the OTG mode.

    Smart power selector is enabled during the OTG modeFigure 34. Smart power selector is enabled during the OTG mode.

    Charger configuration is enabled during the OTG modeFigure 35. Charger configuration is enabled during the OTG mode.

    Demo 6: Initiate the Power Role Swap/Data Role Swap/VCONN Swap
    The MAXREFDES179 reference design board is user-programmable to initiate the power role swap, data role swap, and VCONN swap. Connect to another MAXREFDES179 reference design board and follow the steps to initiate the power role swap:

    1. Setup for the power role swap/data role swap/VCONN swap (Figure 36).
    2. Go to the Command tab and select Send Swap Request (0x37). Select 0x2 = Power Role in the drop down and click Write (Figure 37).
    3. The power role swap request is accepted (Figure 38).
    4. VBUS transitions from the Source to Sink (Figure 39).
    5. USB-C status after the power role swap is successful (Figure 40).

    Setup for the power role swap_data role swap_VCONN swapFigure 36. Setup for the power role swap_data role swap_VCONN swap.

    Send swap requestFigure 37. Send swap request.

    Initiate power role swap is successfulFigure 38. Initiate power role swap is successful.

    VBUS transition from the source to sink after the power role swapFigure 39. VBUS transition from the source to sink after the power role swap.

    USB-C status after the power role swapFigure 40. USB-C status after the power role swap.

    Follow the steps to initiate the data role swap:

    1. Go to the Command tab → Select Send Swap Request (0x37). Select 0x1 = Data Role in the drop down and click Write. The data role swap request is accepted (Figure 41).
    2. USB-C status after the data role swap is successful (Figure 42).

    Initiate data role swap is successfulFigure 41. Initiate data role swap is successful.

    Initiate data role swap is successfulFigure 42. Initiate data role swap is successful.

    Follow the steps to initiate the VCONN swap:

    1. Go to the Command tab → Select Send Swap Request (0x37). Select 0x3 = VCONN in the drop down and click Write. The VCONN swap request is accepted (Figure 43).
    2. VCONN transitions from on to off (Figure 44).
    3. USB-C status after the VCONN swap is successful (Figure 45).

    Initiate VCONN swap is successfulFigure 43. Initiate VCONN swap is successful.

    VCONN transition from on to offFigure 44. VCONN transition from on to off.

    USB-C status after the VCONN swapFigure 45. USB-C status after the VCONN swap.

    Demo 7: Dead-Battery Bootup
    The MAXREFDES179 reference design board supports the dead-battery bootup. Plug in any USB-C PD adapter between 15W to 100W. The default highest PD power profile is 45W (15V/3A). Follow the steps to read the USB-C and charger statuses after the dead-battery bootup:

    • Dead-battery setup – Supply the BATT+ and BATT- pins with 5.5V (the battery is fully depleted when the battery drops below 5.6V). Plug in a USB-C PD power adapter (preferably USB-compliant). Connect the GUI to the reference design (Figure 46).
    • VBUS during dead-battery bootup (Figure 47).
    • Read the USBC Status and observe the VBUS ADC (Figure 48).
    • Go to the Command tab → Select Current SrcCap (0x30) and click Write to read the selected PDO and current source capabilities of the far-end device (Figure 49).
    • Read the charger status and configurations (Figure 50 and Figure 51).

    Dead-battery setupFigure 46. Dead-battery setup.

    VBUS during the dead-battery bootupFigure 47. VBUS during the dead-battery bootup.

    USB-C status after the dead-battery bootupFigure 48. USB-C status after the dead-battery bootup.

    Current SrcCap for the dead-battery bootupFigure 49. Current SrcCap for the dead-battery bootup.

    Charger details during the dead-battery bootup.Figure 50. Charger details during the dead-battery bootup.

    Charger configurations during the dead-battery bootupFigure 51. Charger configurations during the dead-battery bootup.

  •  

    Parametrics

    Input Type Vin(Min) Vin(Max) Iout(Max) Single/Multiple Output Vout(V) Pout(W) Isolated/Non-Isolated Topology
    DC 5 - - - - - - -

    Parametrics

    Input Type DC
    Vin(Min) 5
    Vin(Max) -
    Iout(Max) -
    Single/Multiple Output -
    Vout(V) -
    Pout(W) -
    Isolated/Non-Isolated -
    Topology -

    Maxim Devices (3)

    Part Number Name Product Family Order Design kits and evaluation modules
    MAX77958 Standalone USB Type-C and USB Power Delivery Controller Universal Serial Bus (USB) Buy Now Design Kits
    MAX77960 25VIN 3A/6AOUT USB-C Buck-Boost Charger with Integrated FETs for 2S/3S Li-Ion Batteries Battery Management Buy Now Design Kits
    MAX17320 2S-4S ModelGauge m5 EZ Fuel Gauge with Protector, Internal Self-Discharge Detection, and SHA-256 Authentication Battery Management Buy Now Design Kits

    Maxim Devices (3)

    Part Number Product Family
    Universal Serial Bus (USB)
    Standalone USB Type-C and USB Power Delivery Controller
    Battery Management
    25VIN 3A/6AOUT USB-C Buck-Boost Charger with Integrated FETs for 2S/3S Li-Ion Batteries
    Battery Management
    2S-4S ModelGauge m5 EZ Fuel Gauge with Protector, Internal Self-Discharge Detection, and SHA-256 Authentication

    MAXREFDES179 Related Videos

    View All Videos