INA321 322 a direct drive capacitive input of the A D converter Figure

The INA321/322 is configured to directly drive the capacitive input of an A/D converter. Due to its low output resistance, the INA321/322 can effectively handle high frequency signals and directly drive capacitive loads. The input voltage is amplified by the INA321/322 and outputted to the low-power, high-speed sampling A/D converters ADS7818 or ADS7822. These converters utilize an internal capacitor array (CDAC) for digital-to-analog conversion, allowing the capacitive input to convert the analog signal into a 12-bit digital signal output.

The INA321/322 operational amplifiers are designed to provide high performance in applications requiring the amplification of low-level signals, especially in the presence of capacitive loads. The configuration allows for direct interfacing with the ADS7818 or ADS7822 A/D converters, which are known for their high-speed sampling capabilities and low power consumption.

The ADS7818 and ADS7822 utilize an internal capacitive digital-to-analog converter (CDAC) architecture, which facilitates the conversion process by utilizing an array of capacitors to represent the analog input signal in a digital format. This method is particularly effective in achieving high accuracy and resolution, with a 12-bit output that is suitable for a variety of applications, including data acquisition and signal processing.

When interfacing the INA321/322 with the A/D converters, it is essential to consider the bandwidth and stability of the system, especially when dealing with high-frequency signals. The low output resistance of the INA321/322 ensures that it can drive the input capacitance of the A/D converter without significant signal degradation, maintaining the integrity of the analog signal during the conversion process.

Overall, this configuration is ideal for applications where high-speed data acquisition is required, and the combination of the INA321/322 and ADS7818/ADS7822 provides a robust solution for converting analog signals into high-resolution digital data efficiently. As shown by INA321/322 configured to directly drive the capacitive input A/D converter shown in Fig. Since INA321/322 output is low resistance, and therefore work at high frequ encies can directly drive capacitive loads. Input voltage through INA321/322 amplifies the output directly to the 12 low-power high-speed sampling A/D converter ADS7818 or ADS7822. ADS7818 or ADS7822 internal input capacitor array (CDAC) digital to analog conversion, that is, capacitive input, converts the analog signal A/D converter input 12-bit digital signal output.