Resolver-based applications require the power op amp stage to provide the resolver excitation signal over long cables. In many applications, such as automotive traction inverters, the cables are housed in a harness and a short-circuit condition between different cables in the same harness can occur. In this situation, the output of the ALM2403-Q1 can see a higher voltage than provided at the positive supply pin. This condition causes the body diode in the output stage PMOS to become forward-biased and start conducting. As a precaution, use a blocking diode in series with the positive power supply; see also Figure 8-3.

For related information, see the ALM2403-Q1 Overvoltage Protection of Resolver-Based Circuits application note.