Dear Sir, We encounter problems at the conditioning circuit output and ADC input interface. The application circuit diagram is shown as Fig. 1. We use TI provided code examples from “Slac676d.zip” to perform single A/D conversion simultaneously on a group of 3 channels. A pulse signal inverse injection from the ADC input to the conditioning circuit output is observed on each channel during conversion. This backward injected pulse seriously distorted the conditioning stage output signal. Fig. 2 shows the impact of the distorted signal at test point A. Fig. 3 shows the impact of the distorted signal at test point B. Fig. 4 shows the impact of the distorted signal at test point C. Fig. 5 shows the signal from A2.0+ at test point C with R5 removed. We need solution from TI to eliminate this backward injected pulse signal. Thanks
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