Texas Instruments recommends a 4-layer PCB with a solid ground plane, and to keep the analog and digital signals separate. The analog signals should be routed close to the ADC, and the digital signals should be routed away from the ADC. Additionally, the power supply lines should be decoupled with capacitors and ferrite beads to reduce noise.
The clock signal should be a clean, low-jitter signal with a frequency between 10 MHz and 40 MHz. The clock signal should be routed close to the ADC, and the clock signal return path should be connected to the analog ground plane. Additionally, the clock signal should be decoupled with capacitors to reduce noise.
The recommended input impedance for the ADS5421Y/T is 1 kΩ or higher. A higher input impedance can improve the signal-to-noise ratio (SNR) and reduce the distortion, but it may also increase the settling time. A lower input impedance can improve the settling time, but it may also reduce the SNR and increase the distortion.
The ADS5421Y/T has a built-in offset and gain calibration procedure. The device can be calibrated using an external voltage reference and a calibration signal. The calibration procedure involves applying a known input voltage to the ADC, and then adjusting the offset and gain registers to achieve the desired accuracy. The calibration procedure can be performed using the SPI interface.
The ADS5421Y/T is sensitive to temperature changes, and the performance can be affected by temperature variations. The device has a specified operating temperature range of -40°C to 85°C. The temperature coefficient of the ADC is typically ±1 ppm/°C, and the device can be calibrated to compensate for temperature effects. It is recommended to keep the device away from heat sources and to use thermal management techniques such as heat sinks and thermal interfaces.
ADS5421Y/T datasheet
by Texas Instruments
