The ADS1015-Q1 contains an input multiplexer (MUX), as shown in Figure 10. Either four single-ended or two differential signals can be measured. Additionally, AIN0 and AIN1 may be measured differentially to AIN3. The multiplexer is configured by bits MUX[2:0] in the Config register. When single-ended signals are measured, the negative input of the ADC is internally connected to GND by a switch within the multiplexer.
The ADS1013-Q1 and ADS1014-Q1 do not have an input multiplexer and can measure either one differential signal or one single-ended signal. For single-ended measurements, connect the AIN1 pin to GND externally. In subsequent sections of this data sheet, AINP refers to AIN0 and AINN refers to AIN1 for the ADS1013-Q1 and ADS1014-Q1.
Electrostatic discharge (ESD) diodes connected to VDD and GND protect the ADS101x-Q1 analog inputs. Keep the absolute voltage of any input within the range shown in Equation 1 to prevent the ESD diodes from turning on.
If the voltages on the input pins can potentially violate these conditions, use external Schottky diodes and series resistors to limit the input current to safe values (see the Absolute Maximum Ratings table).