SBAA359B February   2019  – June 2024 AMC1035 , AMC1035-Q1 , AMC1100 , AMC1106E05 , AMC1106M05 , AMC1200 , AMC1200-Q1 , AMC1203 , AMC1204 , AMC1204-Q1 , AMC1210 , AMC1211-Q1 , AMC1300 , AMC1300B-Q1 , AMC1301-Q1 , AMC1302 , AMC1302-Q1 , AMC1303E0510 , AMC1303E0520 , AMC1303E2510 , AMC1303E2520 , AMC1303M0510 , AMC1303M0520 , AMC1303M2510 , AMC1303M2520 , AMC1304L05 , AMC1304L05-Q1 , AMC1304L25 , AMC1304L25-Q1 , AMC1304M05 , AMC1304M05-Q1 , AMC1304M25 , AMC1304M25-Q1 , AMC1305L25 , AMC1305L25-Q1 , AMC1305M05 , AMC1305M05-Q1 , AMC1305M25 , AMC1305M25-Q1 , AMC1306E05 , AMC1306E25 , AMC1306M05 , AMC1306M25 , AMC1311 , AMC1311-Q1 , AMC1336 , AMC1336-Q1 , AMC1411 , AMC3301 , AMC3301-Q1 , AMC3302 , AMC3302-Q1 , AMC3306M05 , AMC3306M25 , AMC3330 , AMC3330-Q1 , AMC3336 , AMC3336-Q1 , ISO121 , ISO122 , ISO124 , ISO224

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction to Isolated Amplifiers
  5. 2Introduction to Isolated Modulators
  6. 3Performance Comparison Between Isolated Amplifiers and Isolated Modulators
  7. 4Isolated Modulators in Traction Inverters
  8. 5Isolated Amplifier and Modulator Recommendations
  9. 6Conclusion
  10. 7Revision History

2 Introduction to Isolated Modulators

Figure 2-1 shows the implementation of an isolated-modulator-based measurement design.

AMC1301-Q1 AMC1302-Q1 AMC1304-Q1 AMC1305-Q1 AMC1311-Q1 Isolated Modulator Implementation Figure 2-1 Isolated Modulator Implementation

The input stage of an isolated modulator is similar to that of an isolated amplifier. The drivers transfer the modulator output across the isolation barrier. The isolated data output DOUT provides a digital bit stream of 1's and 0's at a much higher frequency (up to 20 MHz). The time average of this bit stream output is proportional to the analog input voltage. The measured signal is reconstructed with a digital filter inside the microcontroller families such as the TMS320F2807x and TMS320F2837x, a DSP, or a field programmable gate array (FPGA).