EMI-Hardened Operational Amplifiers for Robust Circuit Design

As the number of electronic devices in the world continues to increase, the issue of Electronic Interference (EMI) between these devices becomes a greater challenge. In response to the growing need for ICs that are resistant to electromagnetic waves, National has developed several op amp families that are hardened to EMI. The LMV851/52/54 low-power CMOS op amps have 8 MHz gain bandwidth, while the LMV861/62 and LMV831/32/34 series have a gain bandwidth of 30 MHz and 3 MHz, respectively.

This paper discusses the sensitivity of op amps to EMI and measuring EMIRR. It explains why designing EMI-robust circuits requires careful selection of the op amp used in the circuit, and how the selection can be made based on the op amp's EMIRR.