The ADS774JU requires careful layout and routing to achieve optimal performance. TI recommends using a 4-layer PCB with a solid ground plane, and keeping 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.
The ADS774JU's analog inputs have a high impedance, which can make them susceptible to noise and interference. To mitigate this, TI recommends using a low-impedance source, such as an op-amp buffer, to drive the analog inputs. Additionally, using a shielded cable and keeping the analog input traces short can help reduce noise pickup.
The ADS774JU requires a specific power-up sequence to ensure proper operation. TI recommends powering up the analog supply (AVDD) first, followed by the digital supply (DVDD), and then bringing the chip select (CS) low. This sequence helps prevent latch-up and ensures that the ADC is properly initialized.
The ADS774JU requires calibration to achieve optimal performance. TI recommends performing a full-scale calibration by applying a known input voltage to the analog inputs and adjusting the offset and gain registers accordingly. Additionally, performing a system calibration by measuring the ADC's output and adjusting the gain and offset registers can help improve accuracy.
The ADS774JU has a maximum sampling rate of 100 kSPS. However, the actual sampling rate may be limited by the system's clock frequency, the analog input bandwidth, and the digital output data rate. TI recommends consulting the datasheet and application notes for specific guidance on achieving the maximum sampling rate.
ADS774JU datasheet
by Texas Instruments
