---
# System prepended metadata

title: Regular Meeting (2022.12.5)
tags: [Regular Meeting, DeWei]

---

# Regular Meeting (2022.12.5)

## About 48 chs. Fanout board

* Some idea
	* +-5V -> +7/+9/+12V...etc (?-> discussion)
		* Dual rail must apply +V and -V regulator
			* Single rail -> 1 +V regulator
			* And FE-prototye only has +V 
		* Swining ISSEU of this [OPA](https://www.ti.com/lit/gpn/opa3692) 
			* It is due to saturation of transistor in OPA
				* further reading: [*rail to rail OPA*](https://tinyurl.com/xmpw5md6)
			* for the +-5V supplied -> +- 3.6V (original adopt)
			* for the +5V supplied -> 1.3V ~ 3.8V output
			* for the +12V supplied ->xV ~ 10V output
		* USB supplies (5V/3A, GaN)
* 1 OPA fanout 4 channels
	* 1 of OPA3692 can fanout 12 channels
		* 48 channels only needs 4 OPA3692
	* Internal fixed resistor
	* About 
* Should I add input OPA as buffer to drive 4 of OPA3692? 
	* Do simulation
* The new solution: *Rail to Rail OPA* and output >200mA per channels 
	* If we don't care about Bandwidth or R/F time
		* Previous desing: 200MHz and R/F ~ 2ns
	* External feedback(gain) resistor is necessary
	* [AD8656](https://www.analog.com/media/en/technical-documentation/data-sheets/AD8655_8656.pdf)
		* 200 NTD/1pcs
		* 2chs.
		* 28 MHz BW
		* Lower noise: f = 1 kHz, 4nV/√Hz; f = 10 kHz, 2.7nV/√Hz
		* Offset: 500uV
		* Slew rate: 11V/us
	* [AD8397](https://www.analog.com/media/en/technical-documentation/data-sheets/AD8397.pdf)
		* 350 NTD/1pcs
		* 2chs.
		* 69 MHz BW
		* Higher noise: f = 100 kHz, 4.5nV/√Hz; 
		* Offset: 2.5mV
		* Slew rate: 32V/us
	* [AD8534](https://www.analog.com/media/en/technical-documentation/data-sheets/AD8531_8532_8534.pdf)
		* 68 NTD/1pcs
		* 4chs.
		* 3 MHz BW
		* Give up noise: f = 1 kHz, 45nV/√Hz; f = 10 kHz, 30nV/√Hz
		* Offset: 35mV
		* Slew rate: 5V/us
###### tags: `Regular Meeting` `DeWei`
