03-09-2015 11:39 PM
Im working on Power Artitecture Design for this board. I took help of TI's Webench. But I think its not optimal and it provide way too many Switching Power Supplies and Regulators.
My doubt is can i have very few power planes in my PCB design that is driven by sam Switching Power Supply/ LDO and give it to different devices requiring the same voltage level. I've read the datasheet of all the devices as well as Zynq PCB design guide. But didnt find anything about it.
Can I do that at all OR what are the design consideration if I choose to do it. Please suggest the reading material on this part of Circuit design or PCB design.
03-10-2015 02:36 AM
Read DS187 (http://www.xilinx.com/support/documentation/data_sheets/ds187-XC7Z010-XC7Z020-Data-Sheet.pdf) for specifications on the different supplies.
Read UG933 (http://www.xilinx.com/support/documentation/user_guides/ug933-Zynq-7000-PCB.pdf) for details on the power system and other PCB issue. Particularly Chapter 3 and 5.
A minimal power supply system might be:
1V for VCCINT/VCCPINT/VCCBRAM (these can share the rail)
1V8 for VCCAUX/VCCPAUX/VCCPLL/VCCADC
then VCCO_DDR depends on memory chosen (e.g. I have used 1V35 for DDR3L but DDR2 could potentially use the 1V8 rail)
and IO banks depending on what external devices you need to interface to (e.g. I have some 3V3 banks)
03-10-2015 12:19 PM
Thank you for the reply.
Ive refered both the documents. But it doesnt talk about my doubt.
My doubt is as follows. ZYNQ VCC_AUX VCC_PAUX VCC_PLL requires 1.8V. Now the PCB guides suggest how to use same power plane for all these supplies.
I use a Power Regulator to drive that plane
But the USB PHY also needs 1.8V supply. Can I connect these requirements to the same plane as the previous?
03-10-2015 01:40 PM
I'm not a Zynq expert, but I think this should be fine.
If VCCPAUX, VCCPLL, and the PS VCCO supplies (VCCO_MIO0, VCCO_MIO1, and VCCO_DDR) have the same recommended voltage levels, then they can be powered by the same supply and ramped simultaneously. Xilinx recommends powering VCCPLL with the same supply as VCCPAUX, with an optional ferrite bead filter.