ADS8354: Termination of negative input when using single-ended input signal

Hello Albin,

The ADS8354 requires a fully differential configuration.  You cannot connect either input to ground and meet the datasheet specifications.

The Vcm specification in the datasheet only allows Vref+/-0.1V or Vref/2+/-0.1V depending on the input range selected.

In order to drive the inputs differentially, you can use the THS4521 fully differential amplifier (Figure 100 in the datasheet), which can be configured as a single-ended input.  Take a look at the following two 'Circuit's' that show how to do this.

http://www.ti.com/lit/an/sbaa264/sbaa264.pdf

http://www.ti.com/lit/an/sbaa246/sbaa246.pdf

Regards,
Keith N.

Precision ADC Applications

Hello Albin,

I also want to point out that we do have a single-ended input version of this ADC; ADS8353. Since you want single-ended inputs, this device may be easier to use in your design. Figure 101 in the datasheet shows how to connect the inputs.

Regards,
Keith