Electronic – Optocoupler (Analog or Digital)


I have got few analog and digital signal that needs to be galvanically isolated. I am thinking to use H11F1M for analog signals. I am not sure how to rig-up the circuit using this device. Specifically bias resistors to be connected on LED and FET side.

And can the same device be used for digital signals also. And what precautions shall I take while using it for analog signals or digital signal.

I want to isolate RSSI generated from AD8367. RSSI vs Voltage graph on Page 10.

Apart from HCNR200 from Avago as a solution.

I got a application note from Silabs which claims to use Si8660 for isolation of analog signal as it has internal RF Modulator and Demodulator based on OOK. But I am not sure whether analog signal can directly be fed to this chip of I need to use some extrnal opamps as shown in the Evaluation Board of Si866x.

Best Answer

I think the analog part might be achievable by using your analog signal as a variable gain amp that has a a constant voltage source as an input, as suggested in the datasheet. I'm not real familiar w/ this IC choice, but it looks doable with the choice of IC (I just don't know how well!). If money were no object, I would have suggested something like an HCNR200 (at least for non-neg signals), but its for production.