Gathering Critical Data for Designing Thermal Management
Finding how much heat your electronic device dissipates and how to calculate max case temperature can sometimes be a pain. Le dispositif que vous utilisez dans votre application dispose généralement d'une fiche technique complète qui accompagne votre achat ou qui est disponible auprès du fabricant. Most electronic device manufacturers are good about making this information available. Other times, you might need to chase down some of this information. You usually can find it from either the manufacturer or the vendor you purchased your devices from.
Terms You’re Looking for in your Datasheet
Generally, these datasheets indicate: power dissipation (W), the maximum junction temperature (commonly °C), and a junction-to-case thermal resistance (generally °C/W) in the "Thermal" section. Hopefully the device manufacturer was kind enough to indicate where this block of information is in the table of contents or made it pop, since this information likes to hide away.
The Actual Math Part: Calculate Max Case Temperature
In order to calculate your maximum case temperature, first multiply the amount of heat the device dissipates by the junction-to-case thermal resistance to get the temperature rise from the junction to case. Soustrayez ensuite cette augmentation de température de la température maximale de la jonction pour obtenir la température maximale du boîtier.
Tjonction-max - (Ɵjonction-au-boîtier*Pdissipation) = Tboîtier-max
In some cases, figuring out what your datasheet is saying can be a trying ordeal. Thermoelectric Coolers (TECs) or Thermoelectric Devices (TEDs) can be doubling confusing since there is a "hot side" and a "cold side," and the control of both sides is critical to function.
Multiple Devices or System Heat Loads
If you have multiple devices or an existing system that you want to cool together, you may want to test your thermal load instead of calculating, especially for retrofit situations.
If All Else Fails
If you need assistance, please don’t hesitate to contact Boyd Design Engineers. They’ve had extensive experience in reading these types of datasheets and help you design the right solution for you.
