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# System prepended metadata

title: HPD project discussion

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# HPD project discussion 
http://hackfoldr.org/apl_hpdproject/
## Discuss
### 20190715
* 參考[Svoboda's Lab](https://hhmi.flintbox.com/#technologies/bc7783b1-259a-4657-8fad-f2034a307e7a)的電路設計:OPA659+OPA693

**1st stage**: OPA657: 10k TIA (BW~1 MHz @ RF 200 kΩ)

**2nd stage**: OPA693: -1x



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| Svoboda Lab | others   | 
| ----------- | -------- |
| OPA657      | [OPA857](http://www.ti.com/lit/ds/symlink/opa857.pdf)   |
| ~~ADA4817~~     | OPA855   |
| ~~OPA818~~      | OPA858   |
| |LTC6268-10

> C6438也有用OPA657 (A57)


**OPA657**: BW~1 MHz @ RF 200 kΩ
**ADA4817-1**: BW~6.4 MHz @ RF 50 kΩ
**LTC6268-10**: BW~4 MHz @ RF 402 kΩ

**OPA858**: BW~100 MHz @ RF 30 kΩ
**OPA855**: BW~100 MHz @ RF 6 kΩ

**江哥: OPA847**: BW~10-20 MHz @ RF 20 kΩ









## Record
### 20190712
加上Cf測試是否可以去掉震盪
> 無法，當電容越大，震幅越大
> 嘗試在輸入SMA直接接上電容(等效HPD電容)，有相似的震盪(~500MHz)，電容值與振幅成反比
### 20190708
用C6438測試我們的推斷是否正確
> 由於C6438電源不好拉，我們使用wei的電路測試(22k)
> 響應不佳
