I have a capacity of 40nF on the S2 pin, charged to a voltage of 3.3V.
The D pin is at GND. The 40nF is then discharged through the analog switch. The peak current will be around 6.6A for a very short time (if the analog switch has 0.5 Ohm resistance). But the datasheet specifies 500mA max. Will the analog switch survive that?
The 500mA in the datasheet refer to a pulse of 1ms with 10% duty cycle, which corresponds to an energy of 1ms * 0.5²A² * 0.5ohms = 125µJ, which heats the component, but which can cool down in the following 9ms of the duty cycle.
The 40nF capacitor only stores an energy of 218nJ at 3.3V and loses about 216nJ in the first 48ns with the typical switch-on resistance of 0.5 Ohm until it reaches a current of 0.5A and a voltage of 0.3V.
I don't see any issue if you repeat that with a max frequency of e.g. 200Hz.
If the problem is resolved, please mark this topic as answered by selecting Select as best. This will help other users find that answer faster.
Good luck!
/Peter
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.