What is TECGAIN of ADN8834 DS?

Hi,

I have a question about TEC controller ADN8834.

I can see an equation of f_0dB in DS at p18.

Can you explain what TECGAIN in it?

from Fig 35, 0dB should  be at 1/(2*pi*R_1*C_1). But f_0dB of equation has x(R_FB/(R_TH + R_x) - R_FB/R)xTECGAIN.

I assume the followings;

1. TECGAIN is a varied value from device itself. It can change by hot mode or cold mode.

2. When users think of PID Compensation, they can ignore x(R_FB/(R_TH + R_x) - R_FB/R)xTECGAIN. The part would be canceled as x1 or very tiny???

Is my assumption correct?

If not, could you explain what it is?

I would like to know

- What is TECGAIN? and how can it be led in calculation?

- Why is x(R_FB/(R_TH + R_x) - R_FB/R)xTECGAIN ignored in Fig 35?

Thank you for your help.