Tolerance in Linear Gain Mode for AD5142A digital potentiometer

Question

Hi, I have checked the datasheet for the ADI542A and have several questions about the Linear Gain Mode: 
 1. What is the tolerance of R_AW, R_WB and R_AB in Linear Gain Mode? 
 2. Can we leave W floating in this mode, so it can act like a 20k rheostat? If that is the case, can I ignore the wiper resistance for R_AB? 
 3. How do you compensate the value with the temperature coefficient? I dont see a formula for it? 
 4. The datasheet mentioned the power sequence for VDD first and then A, W and B? Do you know if this implementation will work i.e putting a 1uF across A terminal and ground.

EZAutoReply · Accepted Answer

Hi CurrentKnguyen , 
 
 What I meant about "using as a standalone" means there's no external resistor used. One example is when using Rwb and Raw as voltage divider (R1 = Rwb, R2=Raw). The tolerance should be negligible in this case. Figure 14 in AN-1169 however shows that due to the switches inside the part, the mismatch increases as the resistance value of Raw decreases. The one you highlighted is referring to a linear response, that is when one resistor is variable, and one is fixed. Using them individually, they would have the nominal resistor tolerance, which is 1% typ and 8% min/max. 
 
 Best Regards, 
 Yokki)

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Tolerance in Linear Gain Mode for AD5142A digital potentiometer