Hi,
I have a question about ADS1298 RLD driving signal derivation.
As shown in datasheet Figure 33 at page 34, signals output from PGAs are configured to connect to RLD_AMP inverted pin ( RLDINV).
If I connect a 3-lead pattern: LA to IN2P, LL to IN3P, RA both to IN2N and IN3N. I expect to make RLD=Gain*(LA+LL+RA).
Per figure 29, I calculate following PGA output signals (I'm not sure if I made error here).
PGA2_P=LA*(1+R2/R1)-RA*(R2/R1),
PGA2_N=RA*(1+R2/R1)-LA*(R2/R1),
PGA3_P=LL*(1+R2/R1)-RA*(R2/R1),
PGA3_N=RA*(1+R2/R1)-LL*(R2/R1),
But by any combination, I can't get a summarion to LA+LL+RA.
e.g. If set RLD_SENSP(2:1) to 0b11, and RLD_SENSN(2:1) to 0b11, I can get a summation to (LA+LL+2*RA).
So I'm confused how to set the RLD_SENSP and RLD_SENSN registers for this connection.
Can anyone help explain this?
Thanks
