Texas Instruments recommends a 4-layer PCB with a solid ground plane, and to keep the analog and digital traces separate. Additionally, use a low-ESR capacitor for the AVDD pin and a 0.1uF capacitor for the REF pin. Route the analog input traces away from the digital traces and keep them as short as possible.
The ADS7816E/250 has a power-on reset (POR) circuit that ensures the device is in a valid state after power-up. However, it's recommended to add an external reset circuit to ensure the device is in a valid state. A simple RC circuit with a 10kΩ resistor and a 10uF capacitor can be used to generate a reset pulse.
The recommended clock frequency for the ADS7816E/250 is between 1MHz and 4MHz. The conversion rate is dependent on the clock frequency, with a higher clock frequency resulting in a faster conversion rate. However, increasing the clock frequency also increases the power consumption.
The ADS7816E/250 outputs 16-bit data in a two's complement format. The output data is available on the DOUT pin and is clocked out on the falling edge of the SCLK pin. The data is output in a serial format, with the most significant bit (MSB) first.
The recommended input range for the ADS7816E/250 is between 0V and VREF (2.5V or 5V). The input range affects the accuracy of the conversion, with a smaller input range resulting in a more accurate conversion. However, a smaller input range also reduces the dynamic range of the converter.
ADS7816E/250 datasheet
by Texas Instruments
