This slide shows the three main differential format types highlighted in this training module, and their relative DC offset (common mode) and voltage swing levels. The first type is low-voltage positive emitter coupled logic (LVPECL) with faster switching speeds and low noise outputs. The second is low-voltage differential signaling (LVDS) which offers low power and low electromagnetic emissions (EMI). The third is high-speed current steering logic (HCSL) which is used for PCI Express and for Intel chipsets.