Assuming G = 20, and the collected ECG data is 16669383 decimal (0b111111100101101011000111); the calculation is as shown below:
---After removing the last 6 digits (3 bits of ETAG, and 3 bits of PTAG), 0b11 1111 1001 0110 1011 = 0x3F96B =260459 in decimal
---Since the data is in 2's complement, the magnitude of the raw data is (2^18-0x3F96B) =1685 in decimal
---and the sampling voltage is obtained: - 1685*2/（20*（2^18-1）)V = -0.64mV.