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cellphone power consumption

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jszair

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What is typical power consumption of a cellphone? Is making phone calls the most power consuming operation a cellphone?
 

Have a look at the battery life of some phones - they usually give the talk time & standby time. With the battery capacity data (in Ah) you can then calculate a rough power consumption. You will find that standby times can be a few weeks and talk times a few hours, so you will see what consumes the most power. The displays consume a lot and bigger displays consume more. WiFi usually consumes more than phone calls, I believe. In standby they can use the signal received strength to reduce the receiver power consumption if the signal is strong.

Keith.
 
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Have a look at the battery life of some phones - they usually give the talk time & standby time. With the battery capacity data (in Ah) you can then calculate a rough power consumption. You will find that standby times can be a few weeks and talk times a few hours, so you will see what consumes the most power. The displays consume a lot and bigger displays consume more. WiFi usually consumes more than phone calls, I believe. In standby they can use the signal received strength to reduce the receiver power consumption if the signal is strong.

Keith.

This is one power consumption breakdown years ago. It has PA current ~200mA which is close to the number I calculated as you suggested.


I checked iphone spec, they listed talk time 7 hours, wifi 10 hours and 3G 6 hours.
So I assume wifi or 3G use power amplifier and are driven directly by battery also, right?
 
There's no such thing as normal. Power levels are "negotiated"
with the base station, to suit the situation. Everybody engineers
to a best-guess "use model" when optimizing efficiency in the
RF section.
 

Referenced to LiIon battery:

GSM phones average about 2.0 mA's in standby. Talk runs between 70 mA to 200 mA depending on PA power level. GSM PA has high burst current during its active slot. 900 MHz PA can draw as much as 1.8 amps for the slot. This can be a problem as battery ages and its Rs increases. When battery degrades to Rs of about 0.35 ohms it usually results in early low batt warning.

CDMA and WCDMA phones average about 3.5 mA in standby. Talk run between 170 mA and 500 mA depending on PA power level.

Smart phones are wildcards. Processors and display can draw significant current from battery depending on use case, from about 15 mA for MP3 play to over 750 mA's for a video record, depending on video accelerator engine within apps processor. The display with backlight draws about 150 mA.
 
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Hi,

From the table shown above, all blocks are below 3V, i.e., these blocks are supplied by a buck converter. I am wondering whether a boost converter is needed in a cellphone? Because I think the LCD screen and the speaker should need a power supply of 3V~4.5V. Anyone knows?

Noah
 

Not required for LCD or audio, but boost is there for white LED backlighting and for USB Vbus when USB on-the-go mastering is included.

There are three or more switcher coils in typical smart phone.
 
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Not required for LCD or audio, but boost is there for white LED backlighting and for USB Vbus when USB on-the-go mastering is included.

There are three or more switcher coils in typical smart phone.

Hi, thanks for your reply.

what is the voltage and current level for white LED and USB Vbus?

what is a switcher coil? Do you mean there are 3 or more converter in a typical cellphone?
 

White LED generally run 3v to 4 v. USB Vbus needs to make the 100 mA output spec with 5vdc.

Yes, switchers with coil, buck and boost. Cap pumps are seldom used because of surge current and poor efficiency.

Almost always buck for CPU core (0.8v to 1.5v), one for I/O's and memory at 1.8vdc, and boost switcher for 5.5 vdc.

Some newer phones with 90 nm RF CMOS have a fourth switcher for RF digital core of 1.2 vdc -1.5 vdc.

An LED 'Torch' for camera flash may have it own boost switcher since it is very high current.

Power consumption is getting out of hand on smart phones. It won't be long before you see little fans in the phone case to cool the inside.
 

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