Fault Injection III: Connecting the MAXIM4619

In my previous post, I detailed some tests into fault injection techniques on the nRF52 family experimenting with crowbar circuits, and ultimately being surprised by the effects of an analog CMOS switch, the MAXIM4619. After observing its higher overvoltage and ringing effects compared to a traditional crowbar circuit, many of you reached out asking how to properly connect the MAXIM4619 in your setups.

The diagram on the left, taken from the datasheet, shows how each pin connects to the various analog CMOS switches implemented by the IC. In addition to the obvious Vcc and GND connections, the diagram displays three different switches, one enable signal used in conjunction with three switch signals labeled A, B, and C.

Each switch has three different connection points: an output (Y, Z, or X) and two additional connections (X0 and X1 for the X switch, Y0 and Y1 for the Y switch, and Z0 and Z1 for the Z switch).

For this example, we will choose the switch in the upper right corner, which consists of X0, X1, X and A.

We will connect the glitching trigger from the ESP32 to the A signal, so each time we want to inject a glitch, it will switch from one position. We also need to Enable all the switches, for that the ENABLE Signal needs to be set to GND.

Then, we will connect X1 to GND, which will create a short to ground when the trigger is injected.

X0 will be left floating, as we do not want any signal going into our glitching point when it is not needed.

Below is a picture showing what this looks like in real life. I hope this helps everyone!