GP2000
GPS Receiver Hardware Design
Application Note
AN4855
ISSUE 2.0
October 1999
This Applications note should be used in conjunction with the following literature (available from
www.zarlink.com)
Data
Part No
Description
Sheet
Reference
GP2010
GP2015
GP2021
P60ARM-B
GPS Orion
GPS RF Front End
GPS RF Front End
12 Channel Correlator
ARM60-B 32 Bit RISC processor
12 Channel Global Positioning System-Receiver Design
DS4056
DS4374
DS4077
DS3553
DS4808
Description
Thisapplicationnoteshowshowtoconstructacomplete12-channelGPSreceiverengineusingtheGP2000chipset
from Zarlink Semiconductor. The GPS Orion is used as the reference for this engine design. The critical part of the
receiver design involves the placement of the RF receiver components in relation to the digital components. This
application note will concentrate on the RF application using the GP2015 RF front-end IC with attention to the digital
application where this is required.
The data in this application note can also be used to set-up the GP2010 RF front-end, which is the sister product
of the GP2015, although there will be differences to pin numbers, and values of peripheral components.
The GPS Orion is a complete 12-channel Global Positioning System receiver design, implemented on a 4 layer
printed circuit board of 95mm x 50mm. It utilises the key components from the GP2000 GPS chipset : the GP2015
ultra-miniature RF front-end with Dynex DW9255 SAW filter, the GP2021 12-channel correlator and ARM 60-B
microprocessor. It uses memory which includes 32-bit wide SRAM, and GPS firmware stored in EPROM. The GPS
Orion operates with a Power Supply Regulator and RS232 support Interface Board. Together with an active GPS
antennawithlownoiseamplifier(LNA),andacomputermonitor,theGPSOrionformsacompleteGPSmeasurement
sensor, which can be integrated into a multitude of navigation applications. Navigation data output can be either
standard NMEA 0183 v2.01, or proprietary ASCII “WINMON” formats. Differential GPS capability has been
implemented. RTCMSC-104correctionscanbeinputtothereceiverwithType1, 2and9messagesbeingextracted.
Components Used
A Block Diagram of the GPS Orion receiver design appears in Figure 1. The GPS Orion receiver board com-
prises the following components:-
ꢀ
GP2015 ultra-miniature GPS RF front-end IC, including:-
RF input bandpass filter and +5V DC active antenna supply
-
ꢀ
ꢀ
DW9255 GPS band-definition SAW filter, supplied by Dynex Semiconductor (www.dynexsemi.com).
GP2021 12-channel correlator IC, including:-
-
-
-
Full memory-management support for the ARM-60B microprocessor
Dual UART serial interface
Real-Time-Clock using 32.768kHz crystal
ꢀ
ꢀ
ARM 60-B 32bit RISC microprocessor IC. Zarlink Part Number: P60ARM-B/IG/GP1N
Memory, including:-
-
-
512kbytes 20ns SRAM
256kbytes EPROM, holding GPS Orion firmware
ꢀ
ꢀ
Sub-miniature 10.000MHz Temperature Compensated Crystal Oscillator (TCXO)
0.22F memory - backup capacitor