Tag
thermal
6 articles.
- AWG wire gauge and current: what actually sets the limit
Why a wire's current rating belongs to its insulation rather than its copper, what the ampacity charts really measure, and why voltage drop usually binds first.
- Choosing a buck inductor: ripple, saturation and heat
Size the inductance from the ripple target, then check the peak against saturation and the RMS against heating — two different ratings that fail differently.
- How much current melts a PCB trace
Onderdonk's equation, where it stops being true, how it compares against IPC's continuous rating, and why a resettable fuse can be slower than the copper.
- LED series resistor: the value, and the current you get
Compute the resistor from headroom, then find why one part number gives a 2:1 current spread on 3.3 V, what an MCU pin really delivers, and when to stop.
- How many thermal vias, and when more stop helping
One 12-mil via is 261 °C/W, sixteen under the pad are 16 °C/W, and the fortieth buys almost nothing. Size the array, the pad and the copper from TI's data.
- θJA is a property of the test board, not of your board
The thermal resistance on the datasheet was measured on a JEDEC board that is not yours. What the number actually contains, and the five terms you control.