GPS: Personal Navigation Device
GPS: Personal Navigation Device
Block Diagram
Design Considerations
Global Positioning System (GPS)technology has matured into a resource that goes far beyond its original design goals of navigation, and asset tracking.GPS Portable Navigation Devices (PND)provide accurate location and integrate many consumer features, as people use GPS to be more productive, and make their automotive commute safer, and easier.
GPS Module and Processor: Accurate location is the main goal of GPS; achieving portability requires smaller size, lower cost, lower power consumption, and higher performance discrete GPS solutions. Sitara ARM® Application Processors are a power-efficient, ARM-based architecture application processor that combines high performance productivity applications with mobile entertainment applications. The NaviLink 5.0 GPS is the smallest GPS solution (board area 25 mm2), the lowest total bill-of-materials, and lowest power consumption. PNDs use other sensors such as altimeter, humidity, temperature and accelerometers to calculate position. Sensor signal conditioning with the PGA30x and ADS78xx family is enable increased accuracy.
Power Management:Special DC/DC buck converters like TPS624xx/TPS65xxx families with advanced dynamic voltage scaling meet the needs of the newest processors. TI’s TPS630xx family offers 96% efficiency over a wide battery voltage range, with input voltage down to 1.8 volts extending battery life and providing support for Li-ion battery technology. For additional low noise power rails the TPS799xx/TPS717xx LDOs are available. Requirements for wall-plug and USB-port charging can be addressed with the bq240xx family. Innovative next-generation gas gauge solutions are offered in the bq275xx using "Impedance Track" to automatically learn/detect battery characteristics.
Audio Considerations:Integrating entertainment applications like music players demands improved audio features such as multi-band equalizers and echo/noise cancellation while maintaining low power consumption. Newer generation TI audio codecs, such as the TLV320AIC3254, process sound with better audio quality and longer battery life. Class-D amplifiers continue to increase in popularity because of their efficiency and their small-footprint packages.
Display/Lighting and Touch Screen Considerations:TI offers touch-screen controller solutions like TSC21xx/TSC23xx with integrated ESD protection. The TSC200x TSCs achieves low power consumption and are immune to vibration and display noise; small-footprint packages are available. LED drivers like TPS61xxx/75xxx offer flexibility and enable pulse-width modulation and digital dimming with up to 32 steps for brightness control in a small, 2x2 mm2 package. TI provides OLED-specific drivers like TPS6114x/6512x. Voltage levels compatibility problems are solved with level shifters such as SN74AVC20Txxx.
Clocks:The CDCE9xx clock families are modular PLL-based low cost, high-performance, programmable clock synthesizers, multipliers and dividers, generating up to 9 output clocks from a single input frequency.
