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Daisy Chained ADG714 Does not Switch ON

Hi,

I have daisy chained 4 ADG714 chips as suggested in figure 8 of the datasheet. I use 10Kohm pull up resistors at each Dout. I want to switch on all of the channels at a given time so my Din is always high ({ 0xFF, 0xFF, 0xFF, 0xFF }). When I want to turn off the switches, I use the reset pin since that is the quickest way to switch off all channels. Right now, I am not using the reset pin because I just want to see if the switches turn ON. 

Here are the signals I generate from a microcontroller: 

zoomed in:

To test my set-up, I connected S1 pin of the first chip to a 1khz, 500mV sinusoid and expected to see that same signal at D1. What I see at D1, is S1/10:

I want to just close all of the 32 channels so that I can see the same signal inputted at the source, at the drain. 

Can you please help me understand what I am doing wrong

Thank you, 

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  • Hi Devang,

    My name is Kevin Chesser and I am the product engineer currently over the ADG7xx series of devices.

    I think when Stephen says a valid write, he is referring to all 8 bits of data being correctly written into the ADG714 switch.

    See an example of a correct write cycle in the timing diagram below:

    Would you have any scope shots of your SPI communication transactions, this may help with the debug of your issue.

    Regards,

    Kevin