This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Please can anyone point me in the direction of the Tj max for the TS5A21366 Analogue Switch?
This data is not in the datasheet, and is needed for derating the part in my application. The only information is the max ambient temperature, and the theta JA, so I can loosely approximate what the junction will rise to, but not the maximum allowed temperature of the junction.
Please refer to this application note Semiconductor and IC package thermal metrics
It is best if you use the RθJA value as a way to compare parts versus using the value as an absolute since the customer’s system PCB design will highly influence this number as stated above.
But if you must have a number using this calculation Tjmax= Ambient Tempmax + Pmax(RθJA) here it is below:
Signal Switch power dissipation and junction temperature calculator.xlsx
The max power for the TS5A21366 can be calculated by
Pmax = (V+max)(I+max) + 2*[(Ino,Inc,Icommax)^2(Ron)]
About 112mW = (5.5 V)(10uA) + 2[(200mA)^2(1.4 Ohm)
Tjmax= Ambient Tempmax + Pmax(RθJA)
Tjmax = (85°C) + (112mW)(253°C/W)
Tjmax = 113.3°C
113.3°C is an approximation of the maximum junction temperature that the device can obtain while operating at its maximum recommended values. The datasheet abs max table states that max storage temperature for the device is 150°C which is well above 113.3°C. This will mean that there is little risk of thermally causing damage while running this part to its maximum recommended values.
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
In reply to Adam Torma:
This response seems to be imply that - (1) the Max Storage Temp and the Max junction Temp are equivalent, in that (2) no damage will occur while powered- up to the max storage temperature and that (3) the part will also operate- up to the max storage temperature, (4) and not experience any reliability issues (such as reduced life). Are all of these statements true for the SN74CB3Q32245ZKER & SN74CB3Q3245RGYR?
In reply to Matt Crum:
In reply to Jason Rubadue:
If the datasheet doesn't rate the performance of the device at 105 deg C ambient temperature range TI cannot guarantee the device performance stated in the datasheet
TI can undertake the effort to characterize the device at higher temperature range but we need to make sure there is the correct business opportunity to offset the cost of properly ensuring the device operation at higher temperature.
There is a way to search for switches and multiplexers on TI.com based on ambient temperature rating. There are 61 switches that can support > 85 deg C ambient temperature. What do you think about the CD4066B or SN74CB3T16210-Q1?
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.