Global Positioning System (GPS) receivers (Rxs) can now be found in many rental cars as well as in high-performance consumer vehicles. And with the availability, low cost, and small size of the PointCharger model SE4100 GPS Rx integrated circuit (IC) from SiGe Semiconductor (Ottawa, Ontario, Canada), GPS Rxs are being integrated into a wide range of electronic devices, including cellular telephones and personal digital assistants (PDAs).
The SE4100 Rx IC (see figure) is the first product in the company's new line of PointCharger GPS devices. It integrates an intermediate-frequency (IF) filter, voltage-controlled oscillator (VCO), oscillator tank circuitry, low-noise amplifier (LNA), phase-locked loop (PLL), and crystal oscillator within a 24-pin LPCC package measuring only 4 × 4 mm. Based on the company's silicon-germanium (SiGe) technology, the Rx shaves current consumption to less than 10-mA current for a voltage source of +2.7 VDC. The SE4100 is designed for voltage supplies of +2.7 to +3.6 VDC.
The SE4100 GPS Rx IC operates at the GPS receive frequency of 1575.42 MHz and requires a reference frequency of 16.368 MHz. The chip provides a digital 4.092-MHz output suitable for GPS baseband ICs. The company offers a GPS reference design based on the SE4100 and the ST20-GP7 baseband controller from ST Microelectronics; the system's total power consumption is less than 120 mW.
The low current and power consumption of the SE4100 makes it suitable for covert and always-on applications. When all circuits are inactive, the Rx IC draws leakage current of only 10 µA, allowing for long storage lifetimes with battery-operated devices. The Rx IC also includes an antenna detect function that can alert a user to a missing or shorted antenna. P&A: $3.50 (10,000 qty); stock. SiGe Semiconductor, Inc., 2680 Queensview Dr., Ottawa, Ontario K2B 8J9, Canada; (877) 602-7443, (613) 820-9244, FAX: (613) 820-4933, e-mail: [email protected], Internet: www.sige.com.