EVAL-LTC4306 no-OS Example Project

See projects/eval-ltc4306 (doxygen) for the Doxygen documentation.

Supported Evaluation Boards

Overview

The EVAL-LTC4306 features the LTC4306, a 4-channel, 2-wire I2C bus and SMBus-compatible multiplexer with bus buffers that provide capacitive isolation between the upstream bus and downstream buses. This evaluation board provides 6-pin PMOD connectors for upstream and downstream connection for compatibility with PMOD form factors such as EVAL-ADICUP3029.

The EVAL-LTC4306 comes with PMOD connectors and 10 kOhm pull-up resistors on both the upstream and downstream side, and 0.1 uF bypass capacitor on the upstream side. The user also has the option to add a 6-pin, 2.54 mm pitch pin header for connection to the GPIO pins for added functionality.

Applications

  • Nested addressing

  • 5 V/3.3 V level translator

  • Capacitance buffer/bus extender

Hardware Specifications

Power Supply Requirements

Each bus can be pulled up to a supply voltage ranging from 2.7 V to 5.5 V, independent of the LTC4306 supply voltage. Jumper configuration (JP1-JP2) allows individual power supplies per downstream bus, shared upstream voltage, or level shifting between different voltage domains. The board includes 0.1 uF bypass capacitors and optional 0805 footprint capacitor locations for additional decoupling.

Board Connectors

  • P1 - 6-pin PMOD upstream connector (SDA, SCL, VCC, GND, ENABLE)

  • P5-P11 - 6-pin PMOD downstream connectors for four buses

  • P3 - GPIO pin header (not pre-soldered)

  • JP6-JP8 - Address configuration headers (ADR0-ADR2)

  • RDY LED - Lights when upstream is disconnected from all downstream buses; turns off when at least one connection is established

No-OS Build Setup

Please see: No-OS Build Guide

No-OS Supported Examples

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

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

Basic Example

The basic example initializes an LTC4306 I2C bus buffer and two MAX5380 DACs, blinks two GPIO-controlled LEDs for status indication, and cyclically enables downstream I2C channels to sequentially set and cycle voltages on each DAC. The example showcases downstream channel switching and multi-DAC control, running continuously while providing error handling and status output through logs.

In order to build the basic example, make sure you have the following configuration in the Makefile:

# Select the example you want to enable by choosing y for enabling and n for disabling
BASIC_EXAMPLE = y

No-OS Supported Platforms

Maxim Platform

Used Hardware

  • EVAL-LTC4306

  • MAX32650FTHR or compatible Maxim feather board

Connections

The Maxim feather boards do not have a PMOD interface, but you may use Dupont female-female cables to make the required connections. The table below shows the connection between EVAL-LTC4306 upstream connector (P1) and the Maxim feather board.

EVAL-LTC4306 Pin (P1)

Maxim FTHR Pin

Function

VCC

3V3

3.3 V Supply

GND

GND

Board Ground

SCL

SCL

Serial Clock

SDA

SDA

Serial Data

Use the PMOD connectors on the EVAL-LTC4306 to connect downstream devices.

Build Command

# remove sp characters from the build directory
make reset
# build the project
make PLATFORM=maxim TARGET=max32650
# flash the code
make run

ADuCM Platform

Used Hardware

Connections

Connect the EVAL-LTC4306 board to the EVAL-ADICUP3029 through the PMOD I2C header (P9). Use the PMOD connectors on the EVAL-LTC4306 to connect downstream devices.

Build Command

# remove sp characters from the build directory
make reset
# build the project
make PLATFORM=aducm3029
# flash the code
make run