Hi all
I have some confusion designing EMG circuit with ADS1291. Please share your valuable opinions.
Application: EMG measuring with 2 electrodes
Chip: ADS1291
Analog power: +1.5~-1.5V(bipolar power supply AVDD:1.5V, AVSS:-1.5V)
Digital power: 3.3V
Questions
1. IN2N, IN2P, PGA2N, PGA2P, RESP_MODN, RESP_MODP
Do these pins should be pulled up high to AVDD or DVDD?
Whate value of a resistor is recommended for weak pull up?
2. Is it necessary to put 1M ohm and 1.5nf across RLDOUT and RLDINV for this application(EMG measuring with 2 electrodes)? I am planning to connect a body reference point to circuit ground so I don't think 1M ohm and 1.5nf across RLDOUT and RLDINV is necessary.
3. Do I have to pull up the VCAP2 as IN2N?
4. If I pull up the PWDN and START pins to DVDD, would it be ok without writing any register and read data as the signal of DRDY pin falls? I mean reading data at default mode(500SPS) without any initialization.
