ADG601: Connection between D and S

Good evening,

I'm using ADG601 as shown in the image above. When I provide an high value to SHDN i can correctly see VBatt = +VH. On the other hand, when I provide a low value to SHDN i can not see +VH = 0 V.

Can someone help me in understand why?

Thank you very much.

Best regards,

Matteo Colombo

  • Hi, Matteo Colombo.

    I have a few questions before I can evaluate the ADG601 performance:

    1. What is the value of VBatt?
    2. What do you see at +VH when SHDN is low?
    3. May I know what is the next stage of +VH connected to? I need to know the load the ADG601 is driving. Please be reminded that the ADG601 has a continuous current specification, S or D of up to 100mA only.  
    4. Also, what is the value meant by "low value to SHDN" mentioned above? According to the datasheet specs, the Maximum Input voltage for Logic 0, VINL, is 0.8V.

    You might want to check these points first so we can ensure that your application set-up is valid.

    Best Regards,

    May

  • Hi May,

    thank you very much for your reply. The answers to your questions are listed here:

    1. Vbatt = 3.3V

    2. with SHDN low I see +VH = 2.53  V

    3. +VH is connected to 6 switches to provide them positive power supply (2 ADG1408 and 4 ADG1404)

    4. the low value provided to SHDN is 0V.

    Best regards,

    Matteo

  • Hi Matteo,

    Is it possible to have a scope shot showing your results? Can you place the scope probes on the nodes VBatt, SHDN, and +VH? IT would be better if you could show the result when you toggle the SHDN node to logic 0.

    Another question would be, what is your power-up sequence? Does SHDN goes before Vbatt is being provided in the system?

    Also, it seems that you are trying to power-up the ADG1408 and ADG1404 at 3.3V. Please have a look at the Power Requirement Table of the Specifications Section of the respective datasheets, it is stated that the ADG1404/08 are operational from 5V to 16.5V in single supply rail. See figures below.

    So if +VH = 3.3V only, it will not power-up the ADG1404 and ADG1408s.

    You might want to have a look at these points too.

    Best Regards,

    May