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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  • 0
    •  Analog Employees 
    on Sep 13, 2017 7:02 PM over 3 years ago

    Hi,

    Figure 8 of the datasheet shows how to address multiple ADG714 using the ADG739, it is figure 7 that should be used for a daisy chain configuration.

    The timing diagram for the ADG714 is generated using a 1kohm pull up resistor on DOUT so by using a 10k resistor the DOUT ready time will be longer than what is specified so may that is having an impact.

    Could you please provide a scope shots of the DOUT signal?

    Regards,

    Stephen

Reply
  • 0
    •  Analog Employees 
    on Sep 13, 2017 7:02 PM over 3 years ago

    Hi,

    Figure 8 of the datasheet shows how to address multiple ADG714 using the ADG739, it is figure 7 that should be used for a daisy chain configuration.

    The timing diagram for the ADG714 is generated using a 1kohm pull up resistor on DOUT so by using a 10k resistor the DOUT ready time will be longer than what is specified so may that is having an impact.

    Could you please provide a scope shots of the DOUT signal?

    Regards,

    Stephen

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