ID 683794
Date 10/31/2022
Public

## OCT Variation after Calibration at Device Power-Up

The OCT resistance may vary with the variation of temperature and voltage after calibration at device power-up.

Use the following table and equation to determine the final OCT resistance considering the variations after calibration at device power-up.

Table 15.  OCT Variation after Calibration at Device Power-Up for Intel® MAX® 10 DevicesThis table lists the change percentage of the OCT resistance with voltage and temperature.
Description Nominal Voltage dR/dT (%/°C) dR/dV (%/mV)
OCT variation after calibration at device power-up 3.00 0.25 –0.027
2.50 0.245 –0.04
1.80 0.242 –0.079
1.50 0.235 –0.125
1.35 0.229 –0.16
1.20 0.197 –0.208
Figure 1. Equation for OCT Resistance after Calibration at Device Power-Up

The definitions for equation are as follows:

• T1 is the initial temperature.
• T2 is the final temperature.
• MF is multiplication factor.
• Rinitial is initial resistance.
• Rfinal is final resistance.
• Subscript x refers to both V and T.
• ∆RV is variation of resistance with voltage.
• ∆RT is variation of resistance with temperature.
• dR/dT is the change percentage of resistance with temperature after calibration at device power-up.
• dR/dV is the change percentage of resistance with voltage after calibration at device power-up.
• V1 is the initial voltage.
• V2 is final voltage.

The following figure shows the example to calculate the change of 50 Ω I/O impedance from 25°C at 3.0 V to 85°C at 3.15 V.

Figure 2. Example for OCT Resistance Calculation after Calibration at Device Power-Up