Thermal Design User Guide: Agilex™ 3 FPGAs and SoCs

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ID 851249
Date 5/12/2025
Public
Document Table of Contents
Document Table of Contents x
1. Introduction to Agilex™ 3 FPGA Thermal Design Guidelines 2. Agilex™ 3 FPGA Mechanical Construction 3. Agilex™ 3 FPGA Compact Thermal Model (CTM) Construction 4. Power and Thermal Calculator (PTC) 5. Thermal Design Process 6. General FPGA Thermal Design Considerations 7. Design Examples 8. Heat Sinks 9. Document Revision History for the Thermal Design User Guide: Agilex™ 3 FPGAs and SoCs A. Agilex™ 3 FPGA Product Keys and Package Drawings
1. Introduction to Agilex™ 3 FPGA Thermal Design Guidelines x
1.1. Thermal Design Requirements 1.2. Thermal Design Flow 1.3. Definitions of Thermal and Power Terms Used in this Document
2. Agilex™ 3 FPGA Mechanical Construction x
2.1. Built-in Temperature Sensors
2.1. Built-in Temperature Sensors x
2.1.1. Agilex™ 3 FPGA Temperature Rating
3. Agilex™ 3 FPGA Compact Thermal Model (CTM) Construction x
3.1. CTM File Format 3.2. Thermal Modeling with the CTM 3.3. CTM Top Temperature, TCASE Virtual Sensor 3.4. Obtaining the CTM
4. Power and Thermal Calculator (PTC) x
4.1. PTC Thermal Tab Parameters 4.2. Thermal Analysis with the PTC 4.3. PTC Thermal Tab Calculation Options 4.4. Thermal Resistances and Low Power Devices 4.5. Sensor Temperatures on the PTC Thermal Tab
5. Thermal Design Process x
5.1. Package Heat Flow Path 5.2. Variables Affecting the Heat Flow Path 5.3. Recommended Thermal Design Method
6. General FPGA Thermal Design Considerations x
6.1. FPGA Power Considerations
6.1. FPGA Power Considerations x
6.1.1. FPGA Maximum Allowed Power Dissipation 6.1.2. Static, Dynamic, and Standby Power 6.1.3. Future-Proofing an FPGA Thermal Design
7. Design Examples x
7.1. Example 1: Find Cooling Solution for Maximum Junction Temperature Limit 7.2. Example 2: Find Available Thermal Margin for Cooling Solution 7.3. Example 3: Find the Ambient Temperature for a Specified Cooling Solution
8. Heat Sinks x
8.1. Attachment Force 8.2. Thermal Interface Material (TIM)
8.2. Thermal Interface Material (TIM) x
8.2.1. Common TIM2 Materials
8.2.1. Common TIM2 Materials x
8.2.1.1. TIM2 Performance Parameters And Challenges 8.2.1.2. Understanding Resistance and Pressure Map Curves
1. Introduction to Agilex™ 3 FPGA Thermal Design Guidelines
2. Agilex™ 3 FPGA Mechanical Construction
3. Agilex™ 3 FPGA Compact Thermal Model (CTM) Construction
4. Power and Thermal Calculator (PTC)
5. Thermal Design Process
6. General FPGA Thermal Design Considerations
7. Design Examples
8. Heat Sinks
9. Document Revision History for the Thermal Design User Guide: Agilex™ 3 FPGAs and SoCs
A. Agilex™ 3 FPGA Product Keys and Package Drawings

2.1. Built-in Temperature Sensors

The Agilex™ 3 FPGA die is equipped with two types of temperature sensors: digital thermal sensors and thermal diode sensors. The locations of these sensors are fixed for each die.
  • Digital thermal sensors (DTS) have no physical connection to device pins, and you must read their output values using temperature sensing software.
  • Thermal diode sensors (TDS) have physical connections to the pins on the FPGA. To these pins you must connect an external temperature-reading device, such as the Maxim Integrated™ Max6581, Max31730, or Texas Instrument™ TMP468 to read the temperatures.

Both digital thermal sensors and thermal diode sensors report the temperature of their physical location on the die, which may or may not be the hottest location on the die. For this reason, the temperature of these sensors is usually less than the maximum junction temperature settings in the PTC.

For more information on temperature sensors, refer to the Sensors section in chapter 4 of: Device Design Guidelines: Agilex™ 3 FPGAs and SoCs .

Thermal diode sensors cannot be calibrated at the factory, and should be calibrated by you for each circuit board design. The choice of the external reader and the board circuitry impacts the accuracy of the results. For further details on calibration of these sensors refer to:

AN 769: Intel FPGA Remote Temperature Sensing Diode Implementation Guide.

Note: Altera recommends that you use digital thermal sensors when possible.

The following table shows the accuracy of the temperature readouts of the digital temperature sensor (DTS). The DTS accuracy includes the effect of the TSD, the ADC, and all circuitry used to output the digital readout. The accuracy presented here is the mean + three standard deviations (µ+3σ) of the population. For sensors outside of this limit, the maximum accuracy allowed is ±5°C. Note that for most of the local sensors, the accuracy improves significantly to ±3°C in the range of 90°C to 100°C.

Table 2.   Agilex™ 3 FPGA Built-in Temperature Sensors
Die Number of Pinned-out Thermal Diode* Sensors Number of Digital thermal Sensors Digital Thermal Sensor Accuracy
90-–100⁰ C -40-–90⁰ C
Agilex™ 3 FPGA fabric core die 2 4–9 +/- 3⁰ C +/- 5⁰ C
* You should calibrate the thermal diode sensor for your design.

The approximate locations of the temperature sensors are shown in the following figure; these can be mapped to the temperature values obtained from the Power and Thermal Calculator (PTC).

Figure 3. A3C-135 Die and Thermal Sensor Locations


Section Content
Agilex 3 FPGA Temperature Rating

Level Two Title