Grounding configuration of Power supply for zyqn7020 Series Z-turn Board Board

Cyrus's 7 series FPGA and Zynq devices creatively integrate analog-to-digital converters and related on-chip sensors (built-in temperature sensors and power consumption sensors). This is a new feature added to the previous generation of products, which can eliminate external ADC devices in the system design and effectively improve the integration of the system.

Tica, sans-serIF "> Zynq device XADC module includes two 12-bit 1 MIPS analog-to-digital converters and related on-chip sensors. The analog-to-digital converter can provide a high-precision analog interface for general purposes for system applications, and all the special pins of the XADC module are located in bank0. The following figure shows the basic input and output requirements of XADC:

There are two recommended configurations: the XADC on the left in the figure is powered by Vccaux (1.8V) and uses an external 1.25V reference source. With an external reference source in terms of accuracy and thermal drift can achieve better performance, a magnetic bead with isolation analog and digital ground, which can avoid the more commonly used analog and digital circuits common ground and the disadvantage of bringing noise into the analog circuit; XADC on the right side of the figure is the reference source with the chip, then the VREFP pin must be connected to the ground as shown in the figure.

The connection manual of zynq VREFP_0 on the schematic diagram of Mir Electronics z-turn board card manual recommends 1.25V reference iput, which belongs to the right side, which is convenient to use internal reference voltage and can meet most of the needs.