Texas Instruments recommends a 4-layer PCB with a solid ground plane, and to keep the analog and digital signals separate. The analog input traces should be short and direct, and the digital output traces should be routed away from the analog inputs. Additionally, decoupling capacitors should be placed close to the device.
The ADS7818E/250 has an internal calibration circuit that is performed during power-up. However, it is recommended to perform an external calibration using an external voltage reference and a calibration resistor to ensure accurate conversions. The calibration procedure is outlined in the datasheet.
The maximum sampling rate of the ADS7818E/250 is 250 kSPS. The power consumption increases with the sampling rate, and at maximum sampling rate, the device consumes around 15 mW. However, the power consumption can be reduced by reducing the sampling rate or by using the device's power-down mode.
The ADS7818E/250 outputs 16-bit digital data in a serial format. The output data is in two's complement format, and the most significant bit (MSB) is output first. The device also has a data-ready pin that indicates when the conversion is complete and the data is ready to be read.
The recommended voltage reference for the ADS7818E/250 is an external voltage reference with a low temperature coefficient, such as the Texas Instruments REF5025. The voltage reference affects the accuracy of the conversions, and a high-quality voltage reference is required to ensure accurate conversions.
ADS7818E/250 datasheet
by Texas Instruments
