Simple way to connect BNC cables to Discovery

Blog Post created by dmercer Employee on Dec 21, 2012

All the connections to the Analog Discovery design module are made though the 30 pin male header (0.1 inch centers) connector. This is a very common, generic connector and is simple to attach wires to as with the various female to female cables supplied in the kit. Double length square male pins are included to change the female end of the wires into male pins that can be easily inserted into the solder-less breadboards often used in the lab for building prototype circuits.

However, there are many cases where unshielded wires with simple male and female square pins are just not sufficient. It might be desirable to connect Discovery to other conventional Lab instruments or generic 1X:10X scope probes for example. Figure 1 is a breakout adapter for female BNC to female 0.025 in. square pin sockets, Pomona model number 5069. lists them for $11.50 each. The length of the leads is longer than you might like for high frequencies but usually the square pin sockets can be removed, the leads shortened and then reattached.


Figure 1 female BNC to female square pin socket adapter

A second alternative is the BNC breakout connector shown in figure 2. It is Pomona model number 4969 BNC Female to 20 AWG leads and lists for slightly less at $7.90. You would of course need to shorten the leads and provide your own female square pin sockets. This might be a better solution if you wanted to use multiple BNC connectors for all the scope and AWG connections into a single multi pin female header and insert that into the Discovery header connector.


Figure 2 female BNC to wire adapter

The Discovery hardware itself is rather small and light weight and special care should be taken when using adapters like these with heavy and stiff coax cables. In some cases it might be desirable or necessary to insert either a series capacitor or resistor between the BNC connector and the Discovery analog input or output pin. These can of course be spliced into the red wire and then insulated with a length of heat shrink tubing.


Similar adapters with male BNC connectors are also available.