Question (14 Jan 2026)
We are interested in the GigaBlox Nano module. Since it is specified not to have a transformer, would it be possible to design a daughterboard with a transformer if required? Does the transformer‑less architecture allow adding transformers on a daughterboard without having to remove the blocking capacitors? We need a 4‑port gigabit switch for a UAV application and plan to design a daughterboard for the GigaBlox Nano with the required connectors and add transformers on the daughterboard.
GigaBlox Nano is designed specifically for customers to embed into their own designs, adding transformers to their baseboard to achieve the galvanic isolation as necessary. We sell a daughterboard for GigaBlox Nano (RJConn). The design files for this board are open source; many of our customers use this to develop their own daughterboard.
You can also find the ECAD symbol and footprint for GigaBlox Nano here. You can import this directly into your ECAD software for your baseboard design.
We also offer a free design review service for GigaBlox Nano baseboards, so you can share your design with us for a full review. We suggest you send your NDA before doing so.
Thank you for the details provided. The GigaBlox Nano does seem ideal for our application.
I would like to confirm whether the series coupling capacitors on the Ethernet lines of the GigaBlox Nano will not be problematic if connected to a transformer on a baseboard? In general, an Ethernet PHY would be directly connected to the transceiver, but due to the transformer‑less architecture this would not be the case. If this is not an issue then it is simple enough for us to do a baseboard design with transformers, extra protection, and the required connectors. A design review would also be ideal.
The series capacitors are not problematic for the transformers on the baseboard. Indeed RJconn uses transformers and works just fine with the series capacitors on GigaBlox Nano. The transformers work on the transmission of AC voltage signals, and the series capacitors do not affect the AC voltage signals, they simply block any DC component (which the transformer would not pass anyway).
In transformerless ethernet it is typical to add a series capacitor just to prevent any DC current flows between two PHYs.
For your design, it is a simple case of importing the GigaBlox Nano footprint, adding the transformers and wiring up the signals, then wiring the other side of the transformers to your connectors. There are of course PCB layout and routing guidelines to follow (specifically achieving 100Ohm differential impedence), in general you can follow the stackup and routing parameters used in the RJConn daughterboard design files.
Happy to assist with the design review; once you’re ready, send us your design files and we will review the portion that applies to GigaBlox Nano.