# Regular Meeting (2022.7.3) * ZyboZ7 * Fanout Board * Jenny's suggestion (Conventional) * TI-Forum * Sim circuit (10MHz/1Vpp SQ. wave with 1ns R/F time) * Other recommend OPA (fixed Gain) ## 1 Zybo-Z7 [Tried here](https://qiita.com/yhmtmt/items/cba5330ad7ded151882d) ## 2 Fanout board ### 2.1 Jenny's suggestion (Conventional) * Branch out for trace (she does not very recommend) * Y shape 120deg obtuse angle (o) * 90deg right angle (x) * 45deg acute angle (x) * Buffer and buffer (she recommend) * 1 -> 2 -> 4 -> 8 totally (1+2+4+8=15) OPA ### 2.2 TI-Forum * [Refer to Here](https://e2e.ti.com/support/amplifiers-group/amplifiers/f/amplifiers-forum/1114448/lmh6722-layout-suggestion-for-fanout-input-opa-v/4130824#4130824) * Can use 90deg right angle * Nearst layout * 1->2\*4 buffer <- this soultion seems be fine ### 2.3 Sim circuit (10MHz/1Vpp SQ. wave with 1ns R/F time) * Official recommend * ![](https://i.imgur.com/Q54iQLx.png) * I'm tuned * ![](https://i.imgur.com/HN1cmO3.png) * Bandwidth could be attenuated while I adopt higher RF, but overshoot colud be fixed (I tried 300~1.5k ohm @10MHz/1Vpp SQ. wave) * ![](https://i.imgur.com/epdAMDw.png) * Add 50-ohm terminated and capacitor(FE-prototype input stage) * ![](https://i.imgur.com/vfzJELR.png) * Seems to be fine (1pF parallel) * ![](https://i.imgur.com/6vtptW1.png) * Can't sim with FE-Board designed terminated and capacitor(1pF +22pF) * ![](https://i.imgur.com/zl8U1A3.png) #### Summery: The result of sim is so beautiful that it scares me * Does not include such informaiton: * Impact of Trace * Impact of crosstalk (20dBc = 10 times of noise/signal) * ![](https://i.imgur.com/6oaTbdd.png) * ![](https://i.imgur.com/wZwLpHd.png) ### 2.4 Other recommend OPA (fixed Gain) * [OPA692](https://www.ti.com/lit/ds/symlink/opa692.pdf?ts=1656728020125&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FOPA692) 1 channel fixed gain OPAmp(General Video Buffer) * [OPA3692](https://www.ti.com/lit/ds/symlink/opa3692.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1656747759816&ref_url=https%253A%252F%252Fwww.mouser.tw%252F) 3 channels fixed gain OPAmp(*VGA* Video Buffer) * Advantage: Easy to layout (Nearst layout) * If I don't layout nearst(Resistor/OPA/Connector), unexpect signal could occure * Disadvantage: Can't change gain for tuning * This time I tuning with 10MHz/1Vpp SQ. wave * Maybe next time our source is 200MHz/3Vpp SQ. wave * For not fixed gain -> Yes! I must tune again (change resistor) * Like the general purpose fanout buffer * For fixed gain -> maybe can't work, need to change OPA * Isn't general purpose ![](https://i.imgur.com/CzRuvZf.png) ![](https://i.imgur.com/Rsr10ol.png) ![](https://i.imgur.com/nLO9iNH.png) ![](https://i.imgur.com/uBVMx8t.png) ###### tags: `Regular Meeting` `DeWei`