---
# System prepended metadata

title: 'Beam Test 2 Board: Test & Correction'
tags: [TestReport, DeWei]

---

## Outline
* Misunderstand:  ~~3 times amplitude~~ -> Amplitude is the same to previous board
* Grounding noise is caused by CF

## Old board

* Grounding noise generated due to w/o CF
  * ![](https://i.imgur.com/3PMHeHs.png)
* 2.1Vpp, 1Hz
* **BW < 1Hz** from old board

| w/ CF 10pF | w/o CF |
| ------ | ------ |
| ![1hz-wcf](https://hackmd.io/_uploads/BkpAEYZk0.png) | ![1hz-wocf](https://hackmd.io/_uploads/SkHRNFbJA.png) |
| Grounding noise - - | Grounding noise++ |
| BW - - | BW ++ |

* **All the above are applicable to *New board* expect BW**

## New board

|   | w/ CF 3pF | w/ CF 10pF | 
|---|-----------|------------|
|1Hz|  ![3pcf-1hz](https://hackmd.io/_uploads/r11gDFbk0.png)   |![10pcf-1hz](https://hackmd.io/_uploads/ByzXUFWJ0.png)|
|10Hz|  ![3pcf-10hz](https://hackmd.io/_uploads/HkYxwKW1C.png)  |![10pcf-10hz](https://hackmd.io/_uploads/r1nQIF-JC.png)|
|100Hz|  ![3pcf-100hz](https://hackmd.io/_uploads/SyAgwFbkA.png) |![10pcf-100hz](https://hackmd.io/_uploads/rklEUKZ1A.png)|

## Summery

* Trying 5pF or 7pF for CFb of new board
* Keeping my design(new board)
  * Don't add buffer for input of ADC
    * ![](https://i.imgur.com/knStuDd.png)
    * 27 ohm Rsource and 100pF Csource
* Green scintillation fiber
  * Need to do scan *R* again
  * Feature: [low lossless of fiber](https://www.kuraray.com/uploads/5a717515df6f5/PR0150_psf01.pdf)