TIDUDA6A December 2017 – January 2022
A typical multichannel system requires multiple rails to power the analog-, digital-, and mixed-signal circuits. The total system power requirement increases depending on the number of channels required. Figure 2-8 and Figure 2-9 show the power supply trees for a typical multichannel system and subsystem.
Figure 2-8 System Power Supply
Figure 2-9 Subsystem Power RailsTo improve system efficiency, downconvert the input DC rail using a DC-DC buck switching regulator and then regulate the voltage using an LDO. The ripple and noise are critical in RF or analog subsystems where low-ripple LDOs are in use. Depending on the system requirements, digital subsystems such as field-programmable gate arrays (FPGAs) or central processing units (CPUs) receive power directly from a switching regulator or through LDOs.