The DS28E18 is a simple communications bridge that resides at a remote SPI or I²C sensor and allows the sensor to be controlled by just two wires coming from the host system. It reduces the wire count from six (for SPI) or four (for I²C). These two wires use Maxim’s 1-Wire protocol that combines power and signal on a single wire, and which is driven by the programmable I/O pins on the host’s microcontroller. The 1-Wire network supports connection lengths up to 100m and 10 sensor nodes or more.

The IC provides a 512-byte command sequencer in SRAM that can be loaded with multiple I²C or SPI commands. Once loaded, the host controller sends a command to execute the sequence, power, and collect data from attached I²C or SPI peripherals. A subsequent 1-Wire command reads collected data. Power for attached sensors or peripherals is sourced from the 1-Wire line making the DS28E18 a very efficient solution to remotely power and control complex I²C or SPI devices such as sensors, ADCs, DACs, and display controllers.

When used as a bridge for I²C slave devices, the DS28E18 communicates at standard mode (100kHz), fast mode (400kHz) or fast-mode plus (Fm+, 1MHz). In SPI mode, multiple clock rates are supported up to 2.3MHz. Configuring for I²C or SPI operation is performed with a 1-Wire command; I²C is the power-on default. When operating in I²C mode, two programmable GPIO pins are available for additional peripheral control.

Each DS28E18 provides a unique and secure 64-bit ROM identification number (ROM ID) that serves as the device's address on the 1-Wire bus. Multiple DS28E18 devices can coexist with other devices in a 1-Wire network and be accessed individually without affecting other devices.​