TIDUF05 August 2022
To achieve a quality output video stream, the output voltage ripple on the AR0820 and DS90UB953-Q1 supplies must be low so that it does not affect the integrity of the high-speed data and internal PLL clocks. Measurements for 3.3-V, 2.8-V, 1.8-V, and 1.2-V rails are shown in Figure 3-6, Figure 3-7, and Figure 3-8, respectively. The rails that impact imager performance are the 2.8-V and 1.2-V rails as they are responsible for providing a clean analog rail and digital supply. The 3.3-V rail powers the entire system and also has excellent ripple performance of 0.5%. As measured, the 2.8-V and 1.2-V rails have a ripple performance of 0.1% and 0.6%, respectively. The 1.8-V rail is significant to the serializer, because it supplies the VDD and VDD_PLL rails. The 1.8-V rail has great voltage ripple performance at 0.7%. The voltage ripple on all rails is low enough for video output to be successfully transmitted.