TI recommends a 4-layer PCB with a solid ground plane, and placing the ADC close to the analog signal source. Decoupling capacitors should be placed as close as possible to the VCC and GND pins. A dedicated analog ground plane is also recommended to reduce noise coupling.
The ADS7818EB/2K5 has an internal calibration circuit that is performed at power-up. However, it's recommended to perform an external calibration using an accurate voltage reference to ensure maximum accuracy. The calibration process involves applying a known voltage to the input and reading the corresponding digital output.
The maximum sampling rate of the ADS7818EB/2K5 is 250 kSPS. However, the power consumption increases with the sampling rate. At 250 kSPS, the power consumption is approximately 15 mW, while at 10 kSPS, it's around 5 mW. The power consumption can be reduced by using the power-down mode or reducing the clock frequency.
The ADS7818EB/2K5 outputs 16-bit digital data in a serial format. The data is transmitted MSB-first, and the output data format can be configured as either straight binary or twos-complement. The digital output data can be interfaced with a microcontroller or FPGA for further processing and analysis.
The recommended input signal range for the ADS7818EB/2K5 is 0 to VREF (2.5 V or 5 V, depending on the configuration). The input impedance should be less than 1 kΩ to ensure accurate conversions. A higher input impedance can lead to signal attenuation and reduced accuracy.
ADS7818EB/2K5 datasheet
by Texas Instruments
