The electromagnetic interference (EMI) rejection ratio, or EMIRR, describes the EMI immunity of operational amplifiers. An adverse effect that is common to many op amps is a change in the offset voltage as a result of RF signal rectification. An op amp that is more efficient at rejecting this change in offset as a result of EMI has a higher EMIRR and is quantified by a decibel value.
Measuring EMIRR can be performed in many ways, but this report provides the EMIRR IN+, which specifically describes the EMIRR performance when the RF signal is applied to the noninverting input pin of the op amp.
This reference design is presented to help application designers and others who are trying to use the MSP430 in a system with an input voltage in the range of 3.6 V to 6.0 V and who are also interested in using a high-efficiency dc/dc converter with integrated FETs for a small, simple design.