The block diagram above shows a very typical application (Tablet PC), which supports numerous interfaces. The EMI / RFI compliance while also staying in compliance with the USB 2.0 specification is addressed by the usage of an LFC Semiconductor Active EMI reduction IC with SAϕIC™ technology (LX308) at the clock source of the ASIC (MCU). This IC is subsequently replaced by a 1st-Gen Active EMI reduction IC from a competitor, configured to achieve comparable EMI/RFI benefits and the comparative results of
1) EMI compliance testing
2) USB compliance testing
are presented below.
|Vdd||Input Frequency||Deviation||Modulation Rate||Dynamic Current|
|3.3V||24 MHz||26.4 KHz||93.77 KHz||4.35mA|