How to save power while shrinking your next mobile design


 

Where did my charger go?  My laptop is running low on battery again as I’m typing this.  We are constantly struggling with battery life in today’s always-on connected world.  Everything we use needs a longer battery life, but also needs a smaller battery.  Impossible you say?  Certainly not, but this trend of shrinking form factor while extending battery life poses a serious challenge for many of today’s circuit designers.

Why can’t I use a smaller battery to make my product smaller?

The largest component of almost every portable product is the battery itself, second only to the screen.  Thus, the easiest way to reduce the form factor of these products is to reduce the battery.  Problem solved!  Right?  Not so fast…by reducing the size of the battery, you are also reducing the capacity of that battery, meaning a smaller battery not hold as much charge as a larger battery will.  This means that you must be more efficient in your power consumption in order to obtain the same lifetime.

How can I be more efficient with my power consumption?

There are two main ways we can extend battery life.  The first is by reducing our active power consumption.  This is done by minimizing the amount of power drawn when you are talking on your smartphone or checking your Facebook news feed.  This can be accomplished by investing in a more efficient processor or more efficient DC/DC converters which consume less quiescent (active) current.  It could also be improved by obtaining a more efficient screen and backlight, or by simply using the device less often (but that’s no fun at all).  The second method to extend battery life is to minimize your power draw when in “standby” or sleep mode.  This is frequently referred to as shutdown current.

Let’s reduce our standby power consumption

One popular method of reducing standby power consumption is through the use of load switches.  A load switch can be used to disconnect power-hungry components from the battery when not in use.  By doing so, you can lower your standby power consumption and extend battery life.  This approach was used to maximize the battery life of our mPOS (Mobile Point of Sale) Power Reference Design.  By connecting the TPS22918 load switch to loads such as the WiFi, Bluetooth and GPRS radios, as well as the LCD screen, we are able to ensure that customers could use their mPOS all day on a single charge.  And when it does come time to recharge, the design also features 15W USB Type-C charging made possible by the TUSB320 and bq25890 battery charger, which dramatically reduces the recharging time.

How does USB Type-C help recharge my battery faster?
By implementing USB Type-C charging on your next design, you are able to charge at a higher wattage than previously possible.  Typical USB chargers today charge at either 2.5W (5V 500mA) or 5W (5V 1000mA), but USB Type-C supports up to 100W (20V 5A) charging!  This dramatically reduces the amount of time that battery powered devices need to remain tethered.

Next time you are faced with the challenge of designing smaller but still needing a long battery life, don’t forget about TI’s broad portfolio, with everything from highly efficient and compact DC/DCs, to battery chargers, USB Type C solutions, and even load switches, TI has the solutions you need to power up your next design. Kick start your design now and download the  mPOS (Mobile Point of Sale) Power Reference Design!

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