AN 944: Thermal Modeling for Intel® Agilex™ FPGAs with the Intel® FPGA Power and Thermal Calculator

ID 683810
Date 3/29/2021

4.3. Thermal Sensor Accuracy

Both digital thermal sensors (DTSs) and thermal sensor diodes (TSDs) have a sensor accuracy of ±5°C. This margin of error means that a reported value of 100°C could actually be as high as 105°C, which might adversely affect the reliability and timing closure of the FPGA. Therefore, you should design for a cooling margin of at least 5°C, to ensure that the resulting cooling solution remains within the margin of error of the sensors, and does not exceed the desired maximum junction temperature.

When using TSDs you must calibrate the external device to your design circuitry. Reported temperatures from the external temperature sensors can be incorrect by 10°C or more, depending on which die temperature is measured. For further detail on the bonded sensors and how to read them, refer to AN 769: Intel FPGA Remote Temperature Sensing Diode Implementation Guide.