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Old May 5th 19, 08:54 PM posted to alt.comp.hardware
Paul[_28_]
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Posts: 1,467
Default Basis of 3.7V & 4.2V mobile battery?

wrote:
Since no reasonable series voltage combination satisfies
Nv=3,7; Mv=4,2
how are these strange voltages achieved, and why?

What semiconductor technology do modern mobiles use:
bipolar, CMOS ... or what?

Where are these topics documented?

TIA.


Keyword: electrochemistry

Sites: # Practical details of batteries
https://batteryuniversity.com/learn/...ased_batteries
# "Characteristics hexagon" for battery chemistries, why we use them
https://batteryuniversity.com/index....of_lithium_ion
# Details of charging
https://batteryuniversity.com/learn/..._ion_batteries

# whizzy chemistry
https://en.wikipedia.org/wiki/Lithium_battery

# list of battery types
https://en.wikipedia.org/wiki/List_of_battery_types

# good stable but half-capacity tech, yard lamps
https://en.wikipedia.org/wiki/Lithiu...sphate_battery

# LiCoO2 is mentioned here, a high capacity but not entirely stable cell.
# Since Cobalt is expensive, other materials are used to cut the cells.
# Probably no Wikipedia article tracks latest chem evolution for these.
# You would need some sort of science journal. Like maybe electrochemistry.
https://en.wikipedia.org/wiki/Compar..._battery_types

*******

Modern mobiles are mostly CMOS. Bipolar for RF amps and radio stuff.
You can do radios in CMOS, but bipolar lasts longer (stable characteristic).
Doing radios in CMOS is "abuse" (and this is not from direct engineering
knowledge, just from observing how long CMOS-only products last, which
is about three months before the RF power level drops).

BiCMOS was discontinued some time ago, but is a great technology
for the engineers who used it. You could drive a 50 ohm line with the stuff.

HBT will run at 100GHz, but is not practical for computing, nor
does Moores law apply. Features are on the order of 2 microns.

CMOS is cheap, which is why we use it. And human psychology is such,
they will optimize the hell out of it, just to make Moores law
continue to hold.

The documentation is, well... everywhere.

Paul