Finding The Right Memory For Your Mobile Phone Design

This white paper provides memory recommendations for basic, feature-rich, and smartphone mobile phone designs. It discusses memory options including SRAM, PSRAM, and Mobile SDRAM and examines how density, system architecture, caching, and burst operation specifications affect your design decision.

One Size Does Not Fit All
Mobile phone designers know that one memory solution does not fit all handset applications. Today's designers—whether they're designing basic phones, feature-rich phones, or smartphones—can choose from a variety of memory products to get the density, bandwidth, architecture, clock frequency, and other features within the specifications that best meet their application requirements. Given the wide range of mobile phone types, one of the biggest challenges for designers is determining which memory device will deliver optimum memory performance and power consumption for their particular system environment.

Phone Types
Mobile phone types range from basic phones with talk-only capabilities to smartphones with large LCDs and full QWERTY keyboards. In between those two extremes is a vast middle tier of feature-rich phones that currently comprises the largest segment of the mobile phone market. Because these varied phone types offer such diverse features and provide such a wide array of functionality, they all require different memory solutions.

Basic phones have minimal memory needs. Talk-only mobile phones require only a small amount of working memory and data storage for saving phone numbers, call logs, and messages. They generally have a polyphonic ringer and support short message service (SMS) for text messaging and multimedia message service (MMS).

Feature-rich phones are in high demand because they provide a greater level of functionality—including Internet browsing, more advanced text messaging, games, downloading and playing music, and digital camera applications—at a relatively low cost. Delivering advanced features in low-cost, high-performance handsets means more complex memory requirements. Mid-range feature phones support game, multimedia messaging, MP3 downloading, and still-picture capabilities. High-end feature phones additionally include VGA color display, video and audio streaming, interactive games, and mobile commerce.

Smartphones are generally recognized as handheld devices that integrate personal information management and mobile phone capabilities in the same device. This typically involves adding phone functions to already capable PDAs or putting "smart" capabilities, such as PDA functions, into a mobile phone. Most smartphones have an LCD screen and a built-in modem, and are capable of Web browsing, sending and receiving e-mail, voice recognition, video and audio streaming, running office applications, video conferencing, and over-the-air synching with a PC.