Datasheet DS28E18 (Maxim)

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DS28E18 1-Wire® to I2C/SPI Bridge with Command Sequencer General Description Benefits and Features
The DS28E18 is a simple communications bridge that re- ● Operate Remote I2C or SPI Devices Using Single- sides at a remote SPI or I2C sensor and allows the sen- Contact 1-Wire Interface sor to be controlled by just two wires coming from the • Extending I2C/SPI Communication Distance host system. It reduces the wire count from six (for SPI) or • Reduce Six Wires (for SPI) or Four Wires (for I2C) four (for I2C). These two wires use Maxim’s 1-Wire proto- to Two Wires col that combines power and signal on a single wire, and • 512-Byte Sequencer for Autonomous Operation of which is driven by the programmable I/O pins on the host’s Attached Devices microcontroller. The 1-Wire network supports connection • Two Configurable GPIO Pins for Additional lengths up to 100m and 10 sensor nodes or more. Peripheral Control The IC provides a 512-byte command sequencer in SRAM that can be loaded with multiple I2C or SPI commands. ● No External Power Required Once loaded, the host controller sends a command to • DS28E18 Parasitically Powered from 1-Wire execute the sequence, power, and collect data from at- • I2C/SPI Peripheral Power Derived from the 1-Wire tached I2C or SPI peripherals. A subsequent 1-Wire com- Line mand reads collected data. Power for attached sensors ● Flexible 1-Wire and I2C/SPI Master Operational or peripherals is sourced from the 1-Wire line making Modes the DS28E18 a very efficient solution to remotely power and control complex I2C or SPI devices such as sensors, • Supports Standard (11kbps) and Overdrive ADCs, DACs, and display controllers. (90kbps) 1-Wire Communication • 100kHz, 400kHz, and 1MHz for I2C Slaves When used as a bridge for I2C slave devices, the • Up to 2.3MHz for SPI Slaves DS28E18 communicates at standard mode (100kHz), fast mode (400kHz) or fast-mode plus (Fm+, 1MHz). In SPI ● Easy to Integrate mode, multiple clock rates are supported up to 2.3MHz. • Small, 2mm x 3mm x 0.75mm, 8-Pin TDFN Configuring for I2C or SPI operation is performed with a Package 1-Wire command; I2C is the power-on default. When oper- • -40°C to +85°C Operation ating in I2C mode, two programmable GPIO pins are avail- • 2.97V to 3.63V Operating Voltage Range able for additional peripheral control. Each DS28E18 provides a unique and secure 64-bit ROM
Ordering Information appears at end of data sheet.
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 ac- cessed individually without affecting other devices.
Applications
● Examining Environmental Conditions ● Accessory Identification and Control ● Equipment Configuration and Monitoring ● Grain Elevator Monitoring 1-Wire is a registered trademark of Maxim Integrated Products, Inc. 19-100832; Rev 0; 6/20 Document Outline General Description Applications Benefits and Features Simplified Application Block Diagram Absolute Maximum Ratings Package Information 8 TDFN-EP Electrical Characteristics Electrical Characteristics (continued) Typical Operating Characteristics Pin Configuration DS28E18 Pin Description Functional Diagram Block Diagram Detailed Description 64-Bit ROM ID Power-Up ROM ID Serialization 1-Wire Bus System Hardware Configuration Transaction Sequence Initialization 1-Wire ROM Function Commands Search ROM [F0h] Read ROM [33h] Match ROM [55h] Skip ROM [CCh] Resume [A5h] Overdrive-Skip ROM [3Ch] Overdrive-Match ROM [69h] 1-Wire Signaling and Timing Read/Write Time Slots Master-to-Slave Slave-to-Master Improved Network Behavior Device Function Commands Command Start (66h) Write Sequencer Command (11h) Read Sequencer Command (22h) Run Sequencer Command (33h) Device Configuration and Status Commands Write Configuration Command (55h) Read Configuration Command (6Ah) Write GPIO Configuration (83h) Read GPIO Configuration (7Ch) Device Status Command (7Ah) Sequencer Commands I2C Sequencer Interface Commands I2C Start Command I2C Stop Command I2C Write Data Command I2C Read Data Command I2C Read Data with NACK End Command SPI Sequencer Commands SPI Write/Read Byte(s) Command SPI Write/Read Bit(s) Command SS_HIGH Command SS_LOW Command Sequencer Utility Commands GPIO_CTRL Write Command GPIO_CTRL Read Command GPIO_BUF Write Command GPIO_BUF Read Command Delay Command SENS_VDD On Command SENS_VDD Off Command I2C Overview I2C Definitions Bus Idle or Not Busy START Condition STOP Condition Repeated START Condition Data Valid SPI Overview SPI Timing SPI Timing Diagram Power-Up of GPIO/I2C Pins Timeout Typical Application Circuits DS28E18 Configured as an I2C Master Typical Application Circuits (continued) DS28E18 Configured as an SPI Master Ordering Information Revision History