What to phone companies use to cool their >1 Watt heat generating components

[ElephantInTheRoom]

Modern phones are packing more and more processor power and RAM in their phones while phones are becoming slimmer.
Apart from more efficient components. I assume there is still a lot of power being dissipated by these components as heat. My question is what is the new cooling tech that is enabling this to happen?
Do phones have elaborate high conductivity heat sinks or are there other thermal management solutions that are becoming more prevalent?

 

[VEBill]

There are several 'Fix It' style websites where pretty much every new phone is immediately disassembled. So you can see precisely what's inside almost any phone.

Based on what I've seen, there are not many (any?) that require thermal compound during reassembly. In other words, not many (any?) heatsinks.

Wasting power as heat wouldn't do much for battery life. On the other hand, some phones reportedly do get warm when in use.

 

[MacGyverS2000]

The processors used in phones are generally COTS parts, in the grand scheme of things. Heat output of each item is surprisingly minimal. These things aren't Pentium 500's cranking through CAD files, they're ARM cores (or similar) which are amazingly efficient.

My guess would be the power amplifiers for the antenna are the most lossy items in there, though I have no hard data near me at the moment to back up such a supposition.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[zeusfaber]

Anecdotally...

The battery on my iPhone evaporates quickest, possibly caused by the phone getting warmest, when I'm using the GPS intensively.

I would look there.

A.

 

[IRstuff]

I would think that portable devices chew up the most power for the display.

when you can be directly jacked into your visual cortex, battery life should improve.

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[MacGyverS2000]

The battery on my iPhone evaporates quickest, possibly caused by the phone getting warmest, when I'm using the GPS intensively.

I would look there.

Watch how much data you use while actively travelling using GPS... I think you'll find quite a bit. And, of course, that data has to travel over your cell connection. Which leads us back to the antenna's PA.

But I do agree, the GPS chip does seem to dump a surprising amount of heat into the palm. 'twould be curious as to which wins out, GPS or PA.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[zeusfaber]

Dan,

Interesting point. I use online (Google or OSM) and offline (OS 1:25k) mapping almost equally. Shouldn't be hard to slip a thermocouple down the back of the case of the phone and see if there's a difference in heat loading.

I'll see if I can find time to give it a go sometime this week.

A.

 

[IRstuff]

Most battery monitor apps tell you the internal temperature of somewhere inside the phone. For example, Battery Monitor shows my phone currently at 31.6 C

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[VEBill]

"...data you use while actively travelling using GPS..."

Some mapping/navigation apps allow one to download the required map 'tiles', in various scales (zoom), in advance over your wifi at home. So that one can use the phone's GPS during an outing, but with zero mobile data used. Several years ago, I did exactly that on a trip to the UK. Zero mobile data used for the entire trip, even while using the phone's GPS to navigate.

But the GPS function by itself, even with the screen being off most of the time, still drained the iPhone's battery in just a couple of hours.

I understand that later generation of GPS chips (or that portions of chips) are getting a better in terms of power. One coworker claims that his smartwatch has a standalone GPS built into the smartwatch itself (I've not yet confirmed).

 

[ElephantInTheRoom]

Anyone have a ball park of how much power a typical smart-phone using GSM, GPS and some processing will emit?
Trying to get a handle of how much heat does a typical phone have to dissipate to not fry the components.

 

[MacGyverS2000]

VE,

GPS on that smart watch, or dead reckoning... the latter obviously doesn't need a GPS chip and can be surprisingly accurate for hours at a time.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[VEBill]

You can look up the battery capacity in any phone (e.g. 2200 mA-hr), multiply the mA-hr spec by the voltage (e.g. 3.7v) to calculate the watt-hours. Then note how many hours the phone battery lasts under various use patterns (it'll vary widely), to reveal the approximate power consumption.

Correct answer would be about a watt (at most, very roughly), or much less on standby.

To calibrate your instincts, think about holding a 7-watt night light incandescent light bulb in your hand. That's 7 watts of power (heat), and it's much too hot to hold.

 

[MacGyverS2000]

I did a random search and SparkFun was at the top... they suggested 30mA @ 3.3V as a typical draw for GPS chips. That's 0.1W, a lot less than I expected.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[Sparweb]

I'm old enough to remember the heavy Motorola phones. Battery pack voltage was about 12V.
Later I got a flip phone, replaced with similar types a few times. Battery voltage about 7V.
Currently using a Samsung S4 mini. Battery voltage 3.8V.


STF

 

[IRstuff]

I think I saw those in a movie ;-)

The first few generations were limited by what components were commercially available.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[Sparweb]

Yeah right IR. It was such a long time ago.

I think my point is: if you want to dissipate less heat, stop generating so much.

STF

 

[IRstuff]

Well, I'll just note that I remember when mobile phones needed a car to carry them around ;-)

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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