Junction Temperature - 2024.1 English

Vivado Design Suite User Guide: Power Analysis and Optimization (UG907)

Document ID
Release Date
2024.1 English

Leakage current increases exponentially with Junction Temperature, which results in higher static power. Junction Temperature depends on various factors: the total power of the device, the cooling system, board selection, and ambient conditions. By default the Junction Temperature is computed based on other Thermal setup inputs: Ambient Temperature, Heat Sink, Board Selection, etc. Because Junction Temperature is directly proportional to total power, it varies when dynamic power increases. It is very important to specify the right Junction Temperature to estimate accurate static power.

Important: Read the Junction Temperature at the time when power is measured on the hardware and overwrite the existing setting in the Report Power dialog box.

To set Junction Temperature in the AMD Vivado™ IDE, enable the Junction Temperature check box in the Environment tab of the Report Power dialog box and enter the value.

Figure 1. Setting Junction Temperature for Report Power
Equivalent Tcl command:
set_operating_conditions -junction_temp 45

You can measure approximate Junction Temperature by placing a simple thermistor or other hand-held temperature measurement device on the AMD device. If one of the AMD Hardware Programing tools is used to program the devices, then you can read the Die Temperature values. For example, ISE-Impact reads Die Temperature values when you select Debug > Read Status Register. Vivado Hardware Manager graphically drafts the Die Temperature plots in the System Monitor Window.