The design procedure for front-port applications is as follows:
- Determine the total number of channels on the board which require a DS280MB810 for signal conditioning. This will dictate the total number of DS280MB810 devices required for the board. It is generally recommended that channels belonging to the same port be grouped together in the same DS280MB810 device. This will simplify the device settings, as similar loss channels generally utilize similar settings.
- Determine the maximum current draw required for all DS280MB810 devices. This may impact the selection of the regulator for the 2.5-V supply rail. To calculate the maximum current draw, multiply the maximum power supply current by the total number of DS280MB810 devices.
- Determine the SMBus address scheme needed to uniquely address each DS280MB810 device on the board, depending on the total number of devices identified in step 1. Each DS280MB810 can be strapped with one of 16 unique SMBus addresses. If there are more DS280MB810 devices on the board than the number of unique SMBus addresses which can be assigned, then use an I2C expander like the TCA/PCA family of I2C/SMBus switches and multiplexers to split the SMBus into multiple busses.
- Determine if the device will be configured from EEPROM (SMBus master mode) or from the system I2C bus (SMBus slave mode).
- If SMBus master mode will be used, provisions should be made for an EEPROM on the board with 8-bit SMBus address 0xA0. Refer to Section 8.4.2 for more details on SMBus Master Mode including EEPROM size requirements.
- If SMBus slave mode will be used for all device configurations, an EEPROM is not needed.
- Make provisions in the schematic and layout for standard decoupling capacitors between the device VDD supply and GND. Refer to Section 10 for more information.