GPS faceoff: Garmin nuvi 750 vs. HP iPaq 310

GPS systems are forecasted to be one of the top growth areas for consumer products in 2008, with a number of different manufacturers offering different approaches to a GPS solution but all having relatively similar form.

The two GPS systems that were specifically analyzed for this teardown were the Garmin nuvi 750 and Hewlett-Packard iPaq 310, two relatively new GPS systems.

Bluetooth out, FM in
The Garmin nuvi has a 4.3-inch screen with a resolution of 480 by 272 pixels. It weighs about 176g and has a 1,250mAh Li-ion battery. The 750 model, however, does not have Bluetooth capabilities like others such as the 760 and 770. It does offer an FM transmitter to help consumers hear the directions over the stereo instead of the internal speaker. One neat feature offered is the route planning, where you can enter in up to 10 different places you want to go on your trip and it will take you to each instead of having to program in your destination at each stop. Of course, during you travels you can also listen to MP3s or audio books, or have a picture slide show going on.


Unlike the 760 and 770 models, Garmin nuvi 750 does not have Bluetooth capabilities.


For the components inside, the heart of the system is a Garmin- and OMAP-branded processor. While the exact part number is not possible to discern based on package markings, a decap of the device reveals that it is the Texas Instruments OMAP1623. This is the same as the OMAP1621, but with 512Mbit of mobile DRAM, based on an ARM9 core and a TI DSP. The same device has been used in a few of Garmin's previous products, like the 200W and 350.

The nuvi 750 GPS functions are controlled by the SiRF StarIII, which combines digital and RF functions in a single package, and runs a 50MHz ARM7 core. Storage relies on 2Gbit of SanDisk iNAND, which is a combination of the NAND flash controller, DRAM and NAND flash. In conjunction with the iNAND there is 512Mbit of DDR mobile RAM from Qimonda. Wolfson' WM8753 serves as voice and audio codec for the speaker.

For the battery Linear Technology puts up its LTC3557 USB power manager and Li-ion charger and three step-down regulators. There is also a National Semiconductor LP3990 150mA linear voltage regulator, providing an accurate output voltage, low noise, and low current. The part offers preset output voltages between 0.8V and 3.3V. It works without a reference bypass capacitor, thereby reducing the parts count.

Better resolution, battery
Physical dimensions are quite comparable between the Garmin nuvi 750 and HP iPaq 310 GPS systems. The iPaq is about 11g heavier at 187g and the screen is also the same size at 4.3 inches. The iPaq 310, however, offers a higher resolution at 800 x 480 pixels. The battery also offers a bit more punch with a 1,700mAh Li-ion battery. As opposed to the nuvi 750, the iPaq does have Bluetooth 2.0, but as mentioned, other nuvi models offer Bluetooth as well.


Although sporting a 4.3-inch screen like the nuvi 750, HP iPaq 310 offers a higher resolution at 800 x 480 pixels.


A glance at the board inside the iPaq quickly shows that it is a bit more complex than the nuvi. First off, we can see a Centrality processor. Centrality was acquired by SiRF last year. The one used here is the Titan dual core running at 600MHz with an ARM11 core.

In conjunction with the GPS capabilities of the Titan comes the 4110L GPS receiver IC from SiGe Semiconductor. This provides an on-chip LNA and a low-IF receiver with a linear AGC and 2bit ADC. Samsung's 4-die SLC offers 2Gbyte of memory in a single package while Micron provides 128Mbit of SDRAM.

Also on board, the Wolfson WM9712 codec controls the I/Os for the touchscreen and speaker while ForteMedia's FM1182 takes care of voice processing and includes echo cancellation and noise suppression. Finally, for Bluetooth connectivity, it has the Cambridge Silicon Radio BlueCore 4.

Really, the only similarity we saw was a design win in both GPS systems from Wolfson, although they were for different functionality. I guess you could say they both have SiRF parts, since Centrality was acquired. Other than that, both companies have really come up with their own spin on how to design a GPS system while still maintaining a relatively similar form factor.

- Gregory A. Quirk
Technical Marketing Manager
Semiconductor Insights