JAJSFT4C August 2018 – June 2019 ADS9224R , ADS9234R
PRODUCTION DATA.
This device supports unipolar, fully differential, analog input signals. Figure 37 shows a small-signal equivalent circuit of the sample-and-hold circuit. Each sampling switch is represented by a resistance (RS1 and RS2, typically 120 Ω) in series with an ideal switch (SW1 and SW2). The sampling capacitors, CS1 and CS2, are typically 16 pF.
During the acquisition process, both inputs are individually sampled on CS1 and CS2, respectively. During the conversion process, both converters convert for the respective voltage difference between the sampled values: VAINP_x – VAINM_x.
Equation 1 and Equation 2 provide the full-scale input range (FSR) and common-mode voltage (VCM), supported at the analog inputs for reference voltage (VREFOUT) on the REFOUT pin.
where
where