Chapter 16:Programmable Power and Temperature-Sensing Diodes in Stratix III Devices

Conclusion

External Pin Connections

The Stratix III TSD, located in the top-right corner of the die, requires two pins for

voltage reference. Connect the TEMPDIODEP and TEMPDIODEN pins to the external

analog-to-digital converter, as shown in Figure16–2.

Figure16–2.TEMPDIODEP and TEMPDIODEN External Pin Connections

Temperat u re

The TSD is a very sensitive circuit which can be influenced by the noise coupled from

traces on the board, and possibly within the device package itself, depending on

device usage. The interfacing device registers temperature based on milivolts of

difference as seen at the TSD. Switching I/O near the TSD pins can affect the

temperature reading. Altera recommends you take temperature readings during

periods of no activity in the device (for example, standby mode where no clocks are

toggling in the device), such as when the nearby I/Os are at a DC state and the clock

networks in the device are disabled.

Figure16–3.TSD Connections

Conclusion

As process geometries get smaller, power and thermal management is becoming more

crucial in FPGA designs. Stratix III devices offer programmable power technology

and selectable core voltage options for low-power operation. Use these features, along

with speed grade choices, in different permutations to get the best power and

performance combination. Taking advantage of the silicon, the Quartus II software is

able to manipulate designs to use the best combination to achieve the lowest power at

the required performance.

For thermal management, use the Stratix III temperature sensing diode with an

external analog-to-digital converter in production devices. This allows you to easily

incorporate this feature in your designs. Being able to monitor the junction

temperature of the device at any time also allows you to control air flow to the device

and save power for the whole system.

Stratix III Device Handbook, Volume 1