Hi,
I am avluating a ADS1298R EVM .
Board inforamtion: ECG FE REV A3, ADS1298R EVM SER #6.
Power settings: DVDD=3v, AVDD=3v, AVSS=0v.
Sample Rate : 8000.
Channel Connection:
// C6- IN1P WCT-IN1M // LA- IN2P RA- IN2M * // LL- IN3P RA- IN3M // C2- IN4P WCT-IN4M // C3- IN5P WCT-IN5M // C4- IN6P WCT-IN6M // C5- IN7P WCT-IN7M // C1- IN8P WCT-IN8M register settings:
ads1298. Registers[REG_CONFIG3] =(PD_REFBUF_ON|VREF_2_4V|RLDMEAS_OPEN|RLDREF_INT_INT|PD_RLD_ON|RLDMEAS_RLDINV);
ads1298. Registers[REG_RLD_SENSP] =(RLDP3|RLDP2);//LL+LA ads1298. Registers[REG_RLD_SENSM] =(RLDM2);//RA // DC Lead off Resistor (note: adds offset) // use 10MΩ pull-up/pull-down resistor. ads1298. Registers[REG_CONFIG4] =(PULSE_MODE_DIS|LOFF_COMP_EN);
ads1298. Registers[REG_LOFF_SENSP]=LOFFP_ALL;
ads1298. Registers[REG_LOFF_SENSM]=LOFFP_ALL;
ads1298. Registers[REG_LOFF_FLIP] =0; //do not flip (pull up on P inputs) ads1298. Registers[REG_LOFF] =(COMP_TH_95|VLEAD_OFF_EN_VOLTAGE|FLEAD_OFF_DC);
The problem is when the RA elec. is connected and LA+LL disconnected i get Lead_OFF signal on RA. But if LA or LL or LL+LA are connected i get correct Lead_ON signal on RA. I can't find where is a problem. I think it some how relay on the fact that only RA is conneted to INM pin and all other to INP pins.
