3 Previous Generations of Texas Instruments Isolated Amplifiers Radiated Emissions Performance

Released in 2018, the ISO224 closely managed the energy crossing over the isolation barrier, and added OOK data transmission. The radiated emissions EMI scan shown in Figure 3-1 was performed using the ISO224 and the emissions are first seen around 540 Mhz with 18 dB of margin and continues to 1 GHz which is the CISPR 11 test limit, with 6 dB of margin at 940 MHz.

Texas Instruments released the AMC1100 and AMC1200 isolated amplifiers in 2011. These devices feature a basic isolation barrier and meet the CISPR 11 Class A and Class B standards with sufficient margin.

As shown in Figure 3-2, the AMC1200 has several radiated emissions peaks above the noise floor, however, there is a significant amount of margin available to the CISPR class B limit shown in black. The noise peaks in the 100 MHz to 230 MHz region have 24 dB of margin from the CISPR11 Class B limit, while the noise peaks in the higher frequency range, 480 MHz to 630 MHz, have 13 dB of margin.

Figure 3-2 AMC1200 CISPR 11 Radiated Emissions EMI Scan