Si838x Isolated Multi-Channel Input Devices for PLC Applications
Created: Jan 23, 2017
No description available.
Programmable logic controllers are devices that are used widely in any production industry or any operation that involves high-end class of input integration. The reference design is an evaluation board for isolated multi-channel input device that can cater up to eight-channels. This design utilizes the Si838x product family, which can provide an eight-channel input for 24V digital field interface to either sinking or sourcing inputs with integrated safety rated isolation.
The reference design is populated with Si8384x that can be powered up with a 5V supply and also provides 8-parallel outputs. The input is bilateral which is 4-channels are for high speed and the other 4-channels is for low speed. The eight input channel isolators can withstand a voltage up to 2.5kV (RMS) and utilized LED emulator inputs to drive the isolation channel. The input interface is based on CMOS based LED emulator technology which enables the bipolar capability (sinking or sourcing inputs) with no VDD required on the field side. The CMOS based LED emulator technology is used for its low power consumption, high-frequency carrier modulation instead of light, fully differential isolation path, and electromagnetic interference design architecture. On the output side, the debounce block controls the amount of debounce desired. There are four debounce delay time options available: no delay, or delays of 10, 30, or 100ms. In addition, the user can use the SPI control to program user-specific debounce modes.
The Si8384x can also be applied to different applications like industrial data acquisition, distributed control system, CNC machine, and motion control system. Product options include parallel or serialized outputs. Cascading capability for a total of 128 channels (16x Si838x) is possible with serial output option. The Si838x offers longer service life and dramatically higher reliability compared to opto-coupled input solutions.