UG-858 has table 1 on page 3 to calculate RV1 and RV2, but sets abitraily RV2=10k which doen't work for most TECs.
Similarly table 2 on page 4 shows RC1 and RC2 for pre-established current ratio.
Equation for flexible V and I ratio shall be supplied and may look like:
Say desired VTECMAXCool = 1.4V, VTECMAXHeat=1.0V
Because of the Avlim=2V/V, one finds
VLIMcool= 0.7V and VLIMheat=0.5V
Since Isink_Vlim = 10uA, one can find
RVp = RV1||RV2 = (VLIMcool - VLIMheat)/Isink_Vlim = (0.7-0.5)/10u = 20kohms
Then one can calculate
RV1 = RVp * (1+ Vratio) = 71.4 kohms
RV2 = RVp * (1 + 1/Vratio) = 27.8 koms
Same principle can be applied for RC1 and RC2 where the Isink_Ilim=40uA.
Corrected with Vratio
[edited by: Optobru at 7:41 PM (GMT -5) on 7 Feb 2022]