q2418130103p
Newbie level 6
Hello,
I plan on implementing a fiber optic channel between two devices.
Based on the speed and distance requirements, I have settled on a receiver, transmitter, and interface circuit recomended by the manufacturer.
I suppose my question boils down to another ananlog vs digital ground question. In the manufacturer document AN1121 (page 5) they show the transmit circuit with the LED (HFBR-14x4z) tied to digital ground (note, the hfbr-15x7z shown in the diagram is meant for an alternate configuration, ignore it). On page 6 they show the receive circuit, with the receiver tied to ananlog ground. Then on page 8, they show that you should tie the 'RxGND' of each circuit together, however this ground was never shown in the transmitter circuit.
In another tech note release by the manfucaturer, Fiber Optic Cookbook, they show the two circuits combined, with both the transmit and receive being tied to analog ground (page 14).
Currently, I am planning on implementing the circuit as shown in the cookbook, I just wanted to see if anyone had thoughts about it, or perhaps an alternate fiber tx-rx solution (noting that 1km, dc-~10MBd is required).
Thanks,
Jay
I plan on implementing a fiber optic channel between two devices.
Based on the speed and distance requirements, I have settled on a receiver, transmitter, and interface circuit recomended by the manufacturer.
I suppose my question boils down to another ananlog vs digital ground question. In the manufacturer document AN1121 (page 5) they show the transmit circuit with the LED (HFBR-14x4z) tied to digital ground (note, the hfbr-15x7z shown in the diagram is meant for an alternate configuration, ignore it). On page 6 they show the receive circuit, with the receiver tied to ananlog ground. Then on page 8, they show that you should tie the 'RxGND' of each circuit together, however this ground was never shown in the transmitter circuit.
In another tech note release by the manfucaturer, Fiber Optic Cookbook, they show the two circuits combined, with both the transmit and receive being tied to analog ground (page 14).
Currently, I am planning on implementing the circuit as shown in the cookbook, I just wanted to see if anyone had thoughts about it, or perhaps an alternate fiber tx-rx solution (noting that 1km, dc-~10MBd is required).
Thanks,
Jay