Electromagnetic interference (EMI) is an important factor to consider for reliable operation of an end product as it may corrupt digital and RF signals inside the system or interfere with the operation of another device nearby. Prior to sale, all information technology equipment (ITE) commonly defined as having a regulated clock signal greater than 9kHz must meet government standards such as FCC Part 15 Subpart B in the United States and EN55022 in the European Union which defines acceptable amounts of radiated energy for industrial and commercial environments (Class A) or home environments (Class B). Linear Technology has decided to test all products to the more stringent Class B limit.