7.3.3 EMI Rejection

The INA165x-Q1 use integrated electromagnetic interference (EMI) filtering to reduce the effects of EMI from sources (such as wireless communications) and densely-populated boards with a mix of analog signal-chain and digital components. The INA165x-Q1 devices are specifically designed to minimize susceptibility to EMI by incorporating an internal low-pass filter. Depending on the end-system requirements, additional EMI filters may be required near the signal inputs of the system; as well as incorporating known good practices, such as using short traces, low-pass filters, and damping resistors combined with parallel and shielded signal routing. Texas Instruments developed a method to accurately measure the immunity of an amplifier over a broad frequency spectrum, extending from 10 MHz to 6 GHz. This method uses an EMI rejection ratio (EMIRR) to quantify the ability of the INA165x-Q1 to reject EMI. Figure 41 and Figure 42 show the INA165x-Q1 EMIRR graph for both differential and common-mode EMI rejection across this frequency range. Table 1 shows the EMIRR values for the INA165x-Q1 at frequencies commonly encountered in real-world applications. Applications listed in Table 1 can be centered on or operated near the particular frequency shown.

Figure 41. Common-Mode EMIRR Testing

Figure 42. Differential Mode EMIRR Testing