GPS solution for $4

Maxim Integrated Products has taken the wraps off a GPS reference design based on its GPS front-end receiver IC combined with Royal Philips Electronics’ Spot GPS software, resulting in a GPS solution for under $4.



The reference design is based on Maxim’s MAX2741 GPS receiver front-end with an on-chip LNA, an adaptive AGC, and VCO. In addition, the MAX2741 has an integrated 1-, 2-, or 3-bit ADC and supports 2MHz to 26MHz reference frequencies with a 2.7V to 3.0V supply voltage.


The Philips Spot software is 600Kb of code written in ANSI C, which can be ported to, and run on any standard processor, such as ARM, Intel Xscale or TI-OMAP. The software takes the output of a GPS front-end receiver and locates the satellites. It then downloads the satellite ephemeris and, using a new proprietary technique, performs signal processing to extract the satellites’ signals. The result is an efficiently generated position fix.



Operating in both autonomous (unassisted) and assisted modes, the software solution can provide fixes every second for applications such as automotive tracking.



The algorithm can also be tuned to suit pedestrian or indoor use, enabling designers to build the GPS into mobile products such as cellular phones, PDAs, digital cameras, MP3 players, laptops, and portable DVD players.