MAX22915 no-OS Example Project

See projects/max22915 (doxygen) for the Doxygen documentation.

Supported Evaluation Boards

Overview

The MAX22915 evaluation kit provides the hardware to evaluate the MAX22915 industrial octal high-side switch with diagnostics. The device is specified for operation with a supply voltage tolerant up to 65V and delivers up to 700mA (min) continuous current per channel with low on-resistance of 120mΩ (max).

Refer to the MAX22915 IC data sheet for detailed information regarding operation of the IC.

Applications

  • Industrial Digital Output Systems

  • PLC Systems

  • Distributed Control Systems (DCS)

Hardware Specifications

Power Supply Requirements

The MAX22915 evaluation kit needs to be supplied with:

  • VL: 3.3V to 5V logic supply

  • VDD: 12V to 65V high-voltage supply

Pin Description

Please see the following table for the pin assignments for the SDP-K1 interface connector. Connect the following pins on the J14 of the MAX22915EVKIT to the SPI pins on the P6 of the SDP-K1.

Pin

Name

Description

1

CS

SPI Chip Select (GPIO)

2

SCLK

SPI Clock

3

MISO

SPI Master In Slave Out

4

MOSI

SPI Master Out Slave In

5

GND

Connect to GROUND

No-OS Supported Examples

The initialization data used in the examples is taken out from: Project Common Data Path

The macros used in Common Data are defined in platform specific files found in: Project Platform Configuration Path

Basic example

This is a simple example which initializes the MAX22915 device and demonstrates:

  • Device initialization with SPI communication

  • Channel configuration and control

  • LED status indicators (FLED and SLED)

  • Diagnostic features (open-wire detection, short to VDD detection)

  • Current and temperature measurement configuration

The example configures all 8 channels as high-side switches and demonstrates basic switch control operations along with diagnostic capabilities.

This example is built by selecting the basic variant (see the Build Command section below).

No-OS Supported Platforms

STM32 Platform

Used hardware

Build Command

For toolchain setup and prerequisites, see the STM32 CMake build guide.

Available variants: basic. Available boards: sdp-ck1z. Replace --variant / --board accordingly.

# set the path to STM32CubeMX and STM32CubeIDE (only if they are not
# in a default install location)
export STM32CUBEMX=</path/to/stm32cubemx>
export STM32CUBEIDE=</path/to/stm32cubeide>
# Windows (PowerShell):
#   $env:STM32CUBEMX = "C:\ST\STM32CubeMX"
#   $env:STM32CUBEIDE = "C:\ST\STM32CubeIDE"

cd no-OS

# build the project (basic example on the SDP-K1 board)
python tools/scripts/no_os_build.py build \
        --project max22915 --variant basic --board sdp-ck1z

# build and flash (requires a connected debug probe)
python tools/scripts/no_os_build.py build \
        --project max22915 --variant basic --board sdp-ck1z \
        --probe openocd --flash

Hardware Setup

For proper operation of the MAX22915 evaluation kit:

  1. Power Supply Configuration: - Connect VDD to 12V-65V high-voltage supply (external) - Ensure proper grounding between all boards

  2. Load Configuration: - Connect appropriate loads to the output channels (CH0-CH7) - Loads should be rated for the operating voltage and current - Use LEDs with series resistors for basic testing

  3. SPI Communication: - Verify SPI connections between SDP-K1 and MAX22915EVKIT - Ensure proper signal integrity with short, direct connections

  4. Safety Considerations: - Use appropriate safety measures when working with high voltages - Ensure proper insulation and grounding - Follow all safety guidelines in the evaluation kit documentation

Example Features

The basic example demonstrates the following MAX22915 features:

  • 8-Channel High-Side Switching: Control of all 8 output channels

  • Diagnostic Capabilities: - Open-wire detection (on/off states) - Short to VDD detection - Overcurrent protection - Thermal protection

  • LED Status Indicators: - Fault LEDs (FLED) for error indication - Status LEDs (SLED) for channel state indication

  • Current Measurement: ADC-based current sensing for each channel

  • Temperature Monitoring: On-chip temperature measurement

  • CRC Protection: Data integrity verification for SPI communication

Usage Notes

  • Ensure proper power sequencing: VL before VDD

  • Monitor thermal conditions during high-current operation

  • Verify load compatibility with 65V maximum voltage rating

  • Use the diagnostic features to ensure system reliability