Shown on this slide is a more detailed block diagram of the different parts to the Si890x evaluation board. The high voltage interface circuit connects directly to the mains line and can interface with both 110 and 220 VAC. The circuit is designed to measure currents up to 10 amps. The jumper blocks allow selection of which device is being evaluated. Jumper selections must be made on both the high voltage side and the low voltage side. The user can select to either evaluate the Si8900 (UART interface), the Si8901 (I²C interface), or the Si8902 (SPI port). The C8051F007 host microcontroller manages the converter under evaluation. It uses its integrated DACs to output analog representations of the line voltage and current reading for analysis with an oscilloscope.