Heat Sink for Zybo

[Yasitha]

I recently purchased a Zybo board and I noticed that its FPGA IC is becoming little hot for a small programs such as blinking an LED. What I would like to know is if I will have to use a heat sink for the chip for more complex and advanced designs?

 

Thanks in advance.

[jpeyron]

Hi @Yasitha,

Welcome to the forums! Did your blink project use the ZYNQ processor or was is purely in the PL? The Zybo has a commercial grade temperature rage of 0 to 85 degrees Celsius as shown here on page 23.  The ZYNQ can sustain up to +85 Celsius degrees operational temperature. There should not be a thermal issues for more complex designs. You can add a heat sink or a small fan, if you fear that the temperature will deteriorate your device. 

cheers,

Jon

[Yasitha]

Hi @jpeyron

Thanks for the reply, I blinked the led using simple verilog code.

 

[jpeyron]

Hi @Yasitha,

We have had a few different heat concerns voiced about a couple of different fpga dev boards but no actual thermal issues that I can remember.

thank you,

Jon 

[david.600]

Hi @jpeyron,

is there a on board sensor on the zynq main chip that measure the temp and shuts down the system if overheated?

If my chip works at 100% cpu and a few more medium size vhdl programs for 5 hours every time,  should i add heat sink?

thanks,

[Lao.Alex.512]

Auto thermal shutdown can be enabled in the bitstream settings but I highly doubt you are going to run into thermal issues. The chip is rated for 85C so until you can burn yourself on the chip you should be OK. You could buy some heatsinks meant for GPU RAM in many places and attach it with thermal tape if you desire. 

[jpeyron]

Hi @david.600,

You can use the xadc to get the temp and can have a flag associated with it. Unfortunately it will not shutdown the system. As mentioned above the ZYNQ chip can sustain up to +85 Celsius degrees operational temperature. If you fear that the temperature will deteriorate your device you can add a heat sink or a small fan.

thank you,

Jon 

[Gau_Veldt]

 

On 12/18/2017 at 12:08 PM, jpeyron said:

Hi @david.600,

You can use the xadc to get the temp and can have a flag associated with it. Unfortunately it will not shutdown the system. As mentioned above the ZYNQ chip can sustain up to +85 Celsius degrees operational temperature. If you fear that the temperature will deteriorate your device you can add a heat sink or a small fan.

thank you,

Jon 

I thought I once read something about a signal available at the PL that tells the Zybo's UART/JTAG driver to reset the PL (ie: same effect as pushing the reset PL button on the board)?  The temp sense could drive that line appropriately and then the PL resets, the prog light goes off and the system idles like it does at power-on (prior to a PL program being loaded). All bets are off though if the PROM boot is being used or the SD boot is used (ie: not jumpered for JTAG mode).  It also occurs to me that on a normal Zybo setup (no external lines, such as from PMODs, providing clocks) one may also assert the ether PHY's reset line which shuts off the master 125 MHz clock to the PL, thus also shutting off all clocks (shutting off clocks shuts off switching which is the source of the heat).