T j max temperature: Reddit — Dive into anything

1 апреля, 2023

Max junction temperature (Tjmax) for LT3086MPFE#PBF — Regarding — Q&A — Power Management

Hi All,

We are planning to use LT3086MPFE#PBF in our application to generate 2.5V ± 3% @ output current of 50 mA (max) with PCB temperature at 110 ºC.  What is the maximum allowed junction temperature (TJMAX) for this device? Is it 150 ºC  or 165 ºC or 125 ºC?

Here are few datasheet points which are confusing.

  1. Note 12 (page 5 of 34) indicates that the device’s internal over temperature circuit will become ACTIVE when junction temperature exceeds 125 ºC for LT3086MP.
  2. Description about TEMP pin indicates that the typical thermal shutdown (thermal limit) temperature is 165 ºC.

Will over temperature circuit internal to the IC be active when Tj is above 125 ºC or will it be ACTIVE when Tj is at 165 ºC for LT3086MPFE#PBF?

Internal thermal limit temperature of 165 ºC seems to indicate that the maximum allowable junction temperature is higher than 125 degC. If it is so, what is the allowed Tjmax for this device?

Thanks

C.Pradeep

  • I will ask the design group to review this post and I will post any significant corrections.

    The LT3086 only has one internal temperature protection threshold — around 165 deg. C.  The 165 deg. C threshold is referenced in the LT3086 datasheet TEMP pin text that I show in the image below.  I agree that Note 12 that you mention seems to imply that there are two internal temperature protection thresholds based on temperature grade, but that is not the case.

    Also LT3086 datasheet Note 3 in the image below that says lifetime is de-rated if the operating temperature is over 125 deg. C, so keep that in mind when you chose between the MP and H temperature grades.    



  • Thank you ARad for the reply. Based on your reply, looks like Max Junction temperature is 165 degC or more. Please confirm on the same.

    We will ensure the heat rise to be so that Tj is 125 degC or less. However, we do not want to provide additional margin of 10degC or 15 degC if maximum Junction temperature is 150 degC or 165 degC.

    Awaiting confirmation/response on the same.

    Thanks

    C.Pradeep



  • Hi C. Pradeep,

    For your design, please consider the operating junction temperature specs as these are what’s guaranteed by design and test. The mention of temperatures higher than these apply to the maximum temperature the device will not be damaged and enter into thermal protection.

    Operating Junction Temperature:
    E-Grade, I-Grade………………………….. –40°C to 125°C
    MP-Grade …………………………………… –55°C to 125°C
    H-Grade ……………………………………… –40°C to 150°C

    If your maximum ambient temperature will produce 110degC of PCB temperature, make sure the junction temp at this point will not exceed the operating junction temp considering some margin of course.


How To Monitor Your CPU’s Temperature

A brand new computer will run super smooth, but over time, it’s normal if you start to experience a bit of sluggishness. This could be due to a variety of factors, such as hard drives degrading, or files that are cluttering up the system processes, or it could be an indication that your computer is overheating.

Overheating is one of the reasons for a computer slowing down, and if you’re looking to keep track of your computer’s performance, checking on the CPU’s temperature is one way to go about it. After all, the CPU is the heart and brain of the computer, so ensuring that it isn’t overheating is always a good idea.

Use Core Temp To Check Your CPU’s Temperature

Core Temp is a pretty useful and free app that you can use if you’d like to get a basic idea on how well your CPU is performing and the temperatures it is hitting. Do note that CPU temperature can fluctuate depending on what you’re doing, where obviously more intensive tasks will increase the heat generated versus when it is idle.

  1. Download and install Core Temp
  2. During the installation process, you might want to uncheck this box if you don’t want additional apps installed
  3. Launch Core Temp

Now, you will see a lot of numbers when the app is installed. You should see the model of the CPU you are using and its platform and frequency. Below it, you will see various temperature readings. To get an understanding of the readings:

TJ. Max – Don’t be alarmed at this number. This is because this number is basically the highest temperature that the manufacturer of your CPU has rated it to run. This means that if you see your CPU hit temperatures that are close to the TJ. Max number, then you should be a little worried as it could be an indication of overheating. It has been suggested that under max load, your CPU temperatures should ideally be 15-20C below the TJ. Max value.

Core – Depending on how many cores your CPU has, this number will vary, but basically each core’s temperature will be shown. If you see differing temperatures among the cores, it is normal as long as the range isn’t too wide. Some potential reasons why some cores run hotter than others is because some cores are designated as the “primary” cores, which means that they are used more often.

It is also possible that during the installation process of your heatsink, you might have applied the thermal paste unevenly or incorrectly. Some have suggested that if this concerns you, then maybe reseating the cooler could help, but we can’t necessarily guarantee that this will even things out.

What Is An Ideal Temperature?

As for “ideal” temperatures, like we said, the max temperature your CPUs should run when under the maximum load should be 15-20C lower than the TJ. Max value, but at the end of the day, the ideal temperature will vary from PC to PC. Laptops, for example, are notoriously bad at cooling compared to desktop builds, so it would be expected and normal for a laptop to run hotter than a PC.

Also, between PCs, it varies because some PCs might use cheaper cooling components, while others might opt for more expensive liquid cooling systems that would obviously perform a lot better.

How To Keep Your PC Cool

Reduce Background Applications

If you’re trying to have your PC run as optimized as possible and under the minimum amount of load, try reducing the number of applications you have running in the background. For example, if you’re playing a game, it might be a good idea to close unnecessary background apps like browsers, video players, and so on. Of course, if you have an extremely powerful rig then this might not apply to you, but for those with regular PCs, it’s not a bad idea to reduce the amount of background processes to reduce the load.

Clean Your PC

Over time, dust gathers and can build around the components of our PCs that will cause it to get hotter. Opening up your case and carefully vacuuming out the dust around the fans and other components can go a long way in preserving your PC and helping it run as cool as possible.

Replace Your Thermal Paste

As we mentioned earlier, one of the reasons why some temperature readings show one core running hotter than the other is due to incorrect application of thermal paste. However, at the same time, if you have been using your PC for years, it might not be a bad idea to replace the thermal paste which would probably have dried up already.

Get A New Cooler

The default CPU cooler than your computer came with is good enough to get the job done, but it’s not necessarily the best. If you find your PC is running too hot, or hotter than you’d like, it might be time for an upgrade. There are plenty of third-party CPU coolers that do a much better job at keeping your CPU cool.

Filed in Computers. Read more about Apps.

Parker Torqmotor TE / TJ / TF / TL / TG ​​/ TH / TK series

The manufacturers of Parker Hannifin’s Torqmotor™ series motors have been producing reliable and accurate parts for over a century. Among the most important events of the past is the first patent for vane rotor sets for low speed, high torque hydraulic motors. It was forty years ago. Today, technological progress goes further.

Specifications:

  • Speed ​​5…1160 rpm
  • Oil consumption max. 75 l/min
  • Supply pressure max. 200 bar
  • Torque max. 550 Nm
  • Side load TE = max. 7000 N, TJ = max. 14,000 N
Designation examples:
vendor code Description
TE0230CW410FSAB TE0230CW410FSAB TORQMOTOR TE230 (SS)
TE0130CW410FSAB TE0130CW410FSAB TORQMOTOR TE130(SS)
TF0130MX080AAAB TF0130MX080AAAB TORQMOTOR MB 130
TF0240HY080AAAB TF0240HY080AAAB TORQMOTOR MB 240
TG0195HY460AAAB TG0195HY460AAAB TORQMOTOR ME 190
TG0785EW441AAAB TG0785EW441AAAB TORQMOTOR ME 790
TG0240EW461AAAB TG0240EW461AAAB TORQMOTOR ME240
TG0475HV080AAFU TG0475 (ESS-G5) TORQMOTOR TG 475
TG0335EX440AAAB TG0335EX440AAAB TORQMOTOR ME 280
TG0170HX080AABP TG0170HX080AABP TORQMOTOR ME 170

The nominal operating temperature must be between +30 and +60°C. The maximum temperature must not exceed +90°C and the minimum must not fall below -30°C. Significantly higher than the rated operating temperature will reduce the life of the oil used. Viscosity in the operating temperature range should be from 20 to 120 mm 2 /s. It is recommended to use a filter with a filtration fineness of 20-50 microns. The technical data refer to operation in motor mode. If the motor is used as a pump, the input torque on the connecting shaft must be limited to the specified maximum value for the operating mode. This requires a suction pressure of 5-10 bar depending on the oil flow (danger of cavitation).

In the research lab, engineers are constantly collecting and analyzing motor data to improve existing products to even higher levels of performance and develop new products to meet ever-changing customer needs. The integrity of the design is ensured by long-term tests on stands to determine the endurance limit. In order to have complete confidence that this will give superior performance, improved production methods are also applied.

As a final check, every motor is tested before being shipped to our customers. Parker understands that if it does not produce quality products, then its customers will not be able to produce quality products.

CPU core temperature — Wiren Board 6

ujin

#1

Hello.
As part of familiarization with the new product, I am interested in the maximum temperature of the processor chip (Tj)
According to the instruction manual, the maximum ambient operating temperature is 85C
According to those documentation for the i.MX 6ULL ​​processor, the maximum power consumption, if you simply sum up all currents x voltages 1.37 W
Thermal resistance when installed on a 4-layer board Ta 32.9 C/W
32.9*1.37 = 45. 1
45.1 + 85 = 130 C0098 In WIKI you described that you tried to operate the processor even at high temperatures. It is also described that in this case the OS reduces performance
What is the maximum consumption that was practically measured (if measured)
What was the temperature of the crystal during tests at maximum processor performance (taking into account interfaces, etc.) . Again, if measured.
I did not find these numbers by searching.
Also, are there such numbers for the new W7 controller.
And the last question regarding the temperature regime.
By how much the temperature will practically change if the controller is installed vertically (rotated 90 degrees along the front axis). Use is assumed in such a position in the system for collecting information not related to any critical processes.
Assumes a maximum operating temperature of about 60 C.
Regards, …

BrainRoot

#2

ujin:

In WIKI you described that you tried to operate the processor even at high temperatures. It is also described that in this case, the OS reduces performance

Yes, to check warming (CPU itself is not capable of warming up at normal temperatures above 90) 

 CPU: Industrial temperature grade (-40C to 105C)CPU Temperature (104C) too cl.
CPU Temperature (109C) too close to max (105C) waiting...
CPU Temperature (110C) too close to max (105C) waiting...
CPU Temperature (111C) too close to max (105C) waiting...
CPU Temperature (111C) too close to max (105C) waiting...

At temperatures above 105, the core stops it.
But the processor itself worked (with disabled protection) up to 130.

ujin:

By how much the temperature will practically change if the controller is installed vertically (rotated 90 degrees along the front axis). Use is assumed in such a position in the system for collecting information not related to any critical processes.

Do not change.

ujin

#3

BrainRoot:

Yes, to check warming up (the processor itself is not able to warm up at a normal temperature above 90)

Thank you.
I wanted to clarify at normal — is it 25C?
Below the temperature rises — this is how I understand the sensors
command in what mode and at what temperature of the ambient air?
105 don’t worry, this is the working mode. In the technical description, the MTBF type parameter is 100 thousand hours.
It’s just that I will definitely have +12 from the environment and about 40 in the room (there are heating sources), Well, the reserve.
130 is from the calculation of the ambient air 85 C
at 60 it seems to fit into 105.

BrainRoot

#4

ujin:

I wanted to clarify at normal — is it 25C?

Up to 40. At temperatures above, if you try to load the processor, the limitation, throttling, starts to work.

ujin:

It’s just that I will definitely have +12 from the environment and about 40 in the room (there are heating sources), Well, the reserve.
130 is from the calculation of ambient air 85 C
at 60 it seems to fit into 105.

In our specifications, the maximum temperature of the environment is 85, the controllers were tested with it. It is important here — if an internal UPS on lithium is used, then it will already limit the temperature.

ujin

#5

Thank you.
Judging by the thorough approach to testing, it is necessary to take a closer look at your equipment for use in our tasks.

1 Like

EvgenyBoger

#6

ujin:

According to the documentation for the i.MX 6ULL ​​processor, the maximum power consumption, if you simply sum all currents x voltages 1.37 W
Thermal resistance when installed on a 4 layer board Ta 32.9 C/W
32.9*1.37 = 45.1
45.1 + 85 = 130 C

This is close to the truth, but

  1. six-layer board
  2. it is really impossible to force the processor to consume so much: there are rather voracious blocks that are not used in WB. For example, a RAM encryption block, a 2D accelerator block.
  3. , just in case, we declare on the controller not 85 degrees, but 75 degrees of ambient temperature.

If you have a task where the temperature in the shield is nominally 70 degrees and above, then I would recommend:

  1. Limit the processor frequency to 530 MHz. At a lower frequency, we lower the voltage of the processor core, so it consumes noticeably less.
  2. Increase core shutdown limit from 105 to 110 degrees. Here the logic is as follows: firstly, the internal sensor of the processor is not very accurate, so it may show less. Secondly, the industrial processor in WB6 has a very large MTBF margin. If you extrapolate the failure curves by 5 degrees, then there will still be a long time. The curves are not at hand now, but they are in the “i.mx6ull lifetime estimation” document on the NXP website.

We will set up both on request, if a real need arises.
But in general, we have never encountered 70 degrees in the shield in real tasks, although customers have, for example, applications in outdoor cabinets without air conditioning on oil rigs in the desert.