---
# System prepended metadata

title: Regular Meeting (2023.3.13)
tags: [Regular Meeting, DeWei]

---

# Regular Meeting (2023.3.13)
* Fanout-48
  * We still needs analog switch
    * Refer to [here](https://e2e.ti.com/support/amplifiers-group/amplifiers/f/amplifiers-forum/1202679/enabling-disabling-op-amp-with-ena-of-ldo/4535293#4535293)
    * >It is not allowed to apply a voltage to a powered-down output, as this can **(partially) power up the opamp**; see figure 63. You need to use an opamp with shutdown function, or add analog switches (2x SN74LV4053A/TMUX1133) to disconnect all I/Os.
  	* ![](https://i.imgur.com/2M26iMn.png)
  	* Although there is no current passing through the +/- In side of OP-AMP whehether power on or power off (MOSFET: Gate to source current -> 0), but inside diode of OP-AMP is *on* state, so OP-AMP is **power up partially**, we would get output which is Vd-on of diode
	* [TMUX1133](https://www.ti.com/lit/ds/symlink/tmux1133.pdf)
		* Bi-direction analog S/W
		* Enable: A -> D
		* Disable: GND -> D
  * Configure:
    * ![](https://i.imgur.com/uqp8Lud.png)
    * ![](https://i.imgur.com/ehTZ5Pq.png)
###### tags: `Regular Meeting` `DeWei`