Cell Phone Connection Failed – AGAIN!?
Friday, July 17, 2009 in Mobile Solutions
By Fairchild Semiconductor
Standing in the park, I have been checking emails, making phone calls and taking a few precious pictures of my darling dog. Wishing to send the pictures to a friend’s cell phone, I press the button and stare at the cell phone display. Suddenly, it says “connection failed.” What! I try again and realize that the cell phone battery is too low with barely one bar showing.
Does this sound familiar to you?
We all want to be connected via cell phone whenever and wherever we are. Unfortunately, our cell phone battery does not always keep up with our busy lifestyle.
Inside of every cell phone is a radio frequency (RF) transmitter. Every time you talk, text or send data, the transmitter drains power from the battery. Often the transmitter consumes only 10% of the phone’s total power. However, if you’re in a poor coverage location, surf the net or up-load photo/video, the transmitter’s battery consumption can top six times, sapping 60% of the battery’s charge. This transmitter can be a huge power drain and dramatically reduce your talk time on the cell phone.
Today’s feature-rich 3G phones require more power than ever before. The design challenge facing engineers today is how to improve efficiency in existing areas such as RFPA, display and increased talk time so more power is available for new features.
One solution is to install a step down DC-DC converter with dynamic voltage scaling to control VOUT between the battery and the RF Power Amplifier (RFPA). This reduces current consumption by 30-50%, and makes power available for other functions (such as MP3, GPS and video). In addition to reducing current consumption, a step down DC-DC converter also reduces heat and increases talk time.
If you would like to check out Fairchild’s solution, please watch a short video demonstrating a solution to extend battery power for a 3G phone by improving the efficiency of the RFPA. More information on RF Power is available at www.fairchildsemi.com/rfpower.
Tags: battery life, cell phone, DC-DC converter, Fairchild, Fairchild Semiconductor, power, RF Power Amplifier, RF transmitter
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