News Archive (1999-2012) | 2013-current at LinuxGizmos | Current Tech News Portal |    About   

Single-chip GPS receiver shrinks

Nov 11, 2008 — by LinuxDevices Staff — from the LinuxDevices Archive — 2 views

Taiwanese vendor SkyTraq has announced a lower-power, higher-performance version of its single-chip GPS receiver for Linux, Windows Mobile, and CE devices. Compared to the earlier Venus634LP, the Venus 634LPx offers better cold start and tracking sensitivity, lower full-power tracking current, and a smaller 1cm2 package, SkyTraq says.

The Venus634LPx appears to be very similar to the Venus634LP that SkyTraq launched in May. Like the earlier receiver, it has a “non-hosted” design requiring no drivers. In fact, besides the chip itself, only a “few passive components” such as an antenna are needed to add GPS capabilities, the company claims (active antennae are also supported).

Function block diagram of the earlier Venus 634LP
(Click to enlarge)

SkyTraq says its new Venus634LPx integrates “all” components needed for GPS reception, including:

  • GPS RF front-end
  • 65 channel GPS/AGPS baseband processor
  • 0.5ppm TCXO
  • RTC crystal
  • LDO regulator

Touted features and specs include:

  • Cold start sensitivity of -148dBm
  • Tracking sensitivity of -161dBm
  • Full-power tracking current of 23mA
  • LGA44 package measuring 10mm x 10mm x 1.1mm
  • 29 second cold start TTFF (time to first fix)
  • Signal parameter search engine performs up to 8 million time-frequency hypothesis tests per second
  • Continuous navigation in harsh environments such as urban canyon and under deep foliage
  • Operating temp. from -30 to 85 deg. C

The Venus634LPx also promises to support an assisted GPS (AGPS) technology called “PromptFixII” that SkyTraq plans to launch in Q1, 2009. However, the technology appears suitable only for applications with “ample” host processing power and memory capacities, SkyTraq says.


The Venus634LPx is sampling now, along with datasheets, reference designs, and evaluation kits. Volume availability is scheduled for next month.

Also available is a Venus634FLPx, featuring user-programmable flash for customized firmware. It, too, comes in the tiny 1cm2 LGA44 package.

This article was originally published on and has been donated to the open source community by QuinStreet Inc. Please visit for up-to-date news and articles about Linux and open source.

Comments are closed.