Hi TI，
The following picture shows the application circuit of AFE4900. The first picture is the electrode input circuit. The second chapter is AFE4900 circuit.
Question 1: How is ECG lead off detection implemented? Is the register status set and read through IIC?
Question 2: The YY9706-247 2021 standard requires that the input impedance of ECG acquisition is greater than 10M At present, the test input impedance is insufficient. The circuit was checked and two 10M resistors, R60 and R62, were removed. The input impedance has improved. However, it still does not meet the standards. The question here is whether the input impedance is related to the lead shedding detection setting? As shown in the following specification, there is current flow on the red line path, resulting in reduced input impedance.
Question 3: Is the RLD connection reasonable? Can it be connected to ground through capacitance?
Question 4: Is there anything else that will affect the input impedance?
