ZHCSJC0 January 2019 ADS1260-Q1 , ADS1261-Q1
ADVANCE INFORMATION for pre-production products; subject to change without notice.
The ADC incorporates two current sources that are used to provide excitation current to a resistive temperature device (RTD), thermistor, diode and other sensor type that require constant current biasing. The currents are programmable over the 50 μA to 3000 μA range and are internally multiplexed to all analog input pins. The current source multiplexer is shown in Figure 19. The IMUX1 and IMUX2 register bits connect the corresponding current source to the analog inputs. The IMAG1 and IMAG2 register bits program the corresponding current magnitude.
Enable the internal reference for current source operation. The current source value can be doubled or an intermediate value produced by connecting the current sources to the same analog input. Take care not to exceed the current source compliance voltage range. That is, when the current source is loaded by resistance, the voltage at the pin increases and must not exceed specification; otherwise the specified current source accuracy is not met.