---
# System prepended metadata

title: Regular Meeting (2022.7.3)
tags: [Regular Meeting, DeWei]

---

# 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`