Document
FEBRUARY 1994
DS3605-2.2
GP1020
SIX-CHANNEL PARALLEL CORRELATOR CIRCUIT FOR GPS OR GLONASS RECEIVERS
The GP1020 is a six-channel CMOS digital correlator which has been designed to work with the GP1010 L1-channel downconverter or other integrated circuits, and may be used to acquire and track the GPS C/A code or the GLONASS signals. For each of the six channels the GP1020 includes independent digital down-conversion to baseband, C/A code generation, correlation, and accumulate-and-dump registers. The GP1020 interfaces with a microprocessor via a 16-bit data bus to control the acquisition and tracking processes using the various registers on the chip.
90
61
91
60
FEATURES
GP1020
s Six Fully Independent Correlation Channels s Switchable to Receive GPS or GLONASS Codes s Input Multiplexer for Multiple GPS Front-Ends – Allows
Antenna Diversity
120
31
s Input Multiplexer for GLONASS Multiple (Separate
Channels) Front-Ends
s Digital Interface Compatible with Most 16 or 32-Bit
Microprocessors
1
30
GP120
Fig 1 Pin connections - top view
s Fully Compatible with GP1010 GPS Receiver Front-End s Sideways Stackable to give Multiples of Six Channels s 120-pin Plastic Quad Flatpack s Power Dissipation Less Than 500mW
APPLICATIONS
ABSOLUTE MAXIMUM RATINGS
These are not the operating conditions, but are the absolute limits which if exceeded, even momentarily, may cause permanent damage. To ensure sustained correct operation the device should be used within the limits given under Electrical Characteristics. Supply voltage (VDD) from ground (VSS): 20·3V to16·0 V Input voltage (any input pin): VSS20·3V to VDD10·3 V Output voltage (any output pin): VSS20·3V to VDD10·3 V Storage temperature: 255°C to 1125°C
s GPS or GLONASS Navigation Systems s High Integrity Combined Receivers s GPS Geodetic Receivers s GPS Time Reference
ORDERING INFORMATION
The GP1020 is available in 120-pin Quad Flatpacks (Gullwing formed leads) in both Commercial (0 °C to 170°C) and Industrial (240°C to 185°C) grades. The ordering codes below are for standard screened devices.
RELATED PRODUCTS
Part Description Datasheet Reference DS3861 DS3076
ORDERING CODES
GP1020 CG GPKR Commercial - Plastic 120-pin QFP (GP120) GP1020 IG GPKR Industrial - Plastic 120-pin QFP (GP120)
DW9255 35·42MHz SAW Filter GP1010 GPS Receiver Front-End
GP1020
TYPICAL GPS RECEIVER (Fig. 2)
All satellites use the same L1 frequency of 1575·42MHz, but different Gold codes, so a single front-end may be used. To achieve better sky coverage it may be desirable to use more than one antenna, in which case separate front-ends will be needed.
GND MASTER CLK SAMPLE CLK SIGN MAG VSS 15V VDD MASTERRESET NAVIGATION SOLUTION
GP1010 & FILTER
MASTER/SLAVE
CS
DECODE DATA BUS (16) ADDR BUS (8) CONTROL
SIGN 0 MAG 0 SIGN 1 MAG 1
GP1020 (MASTER)
TIC OUT INT OUT
MICROPROCESSOR SYSTEM
3
MULTIPLE ANTENNAS TO GIVE WIDER SKY COVERAGE
SLAVECLK
TIC IN SIGN 0 MAG 0 SIGN 1 MAG 1 INT IN
OPTIONAL SECOND GP1010 & FILTER
CS
DECODE
OPTIONAL SECOND GP1020 (SLAVE)
VSS
VDD MASTER/SLAVE
15V
GND
MASTERRESET
Fig. 2 GPS receiver simplified block diagram
TYPICAL GLONASS RECEIVER (Fig. 3)
Each satellite will use a different ‘L1’ carrier frequency, in the range 1602·5625 to 1615·500MHz, with 0·5625MHz spacing, but all with the same 511-bit spreading code. The normal method for receiving these signals is to use several front-ends, perhaps with the first LNA and mixer common, but certainly with different final local oscillators and mixers.
GLONASS FRONT-END FILTERS, AMPLIFIERS AND MIXERS
CHANNEL SELECTION AND ADC CHANNEL SELECTION AND ADC CHANNEL SELECTION AND ADC CHANNEL SELECTION AND ADC CHANNEL SELECTION AND ADC FREQUENCY GENERATOR CHANNEL SELECTION AND ADC SAMPLE CLK SIGN MAG SIGN MAG SIGN MAG SIGN MAG SIGN MAG SIGN MAG
GND VSS
15V VDD
MASTER/SLAVE
L-BAND DOWN CONVERTER
SAMP CLK SIGN 0 MAG 0 SIGN 1 MAG 1 SIGN 2 MAG 2 SIGN 3 MAG 3 SIGN 4 MAG 4 SIGN 5 MAG 5
NAVIGATION SOLUTION MASTERRESET
CS
DECODE
MICROPROCESSOR SYSTEM
DATA BUS (16)
GP1020
ADDR BUS (8) CONTROL 3 INT OUT
MASTER CLOCK
OSCILLATOR FREQUENCY SELECTION
Fig. 3 GLONASS receiver simplified block diagram
2
GP1020
PIN DESCRIPTIONS (See Application Notes, p. 41)
All VSS and all VDD pins must be used in order to ensure reliable operation. Several pins, such as Satellite Inputs 2 to 9 Sign and Magnitudes are also used for device testing, but only as a secondary function. Pin No.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Pin No.
66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
Signal name
TICIN TICOUT D0 D1 VSS VDD D2 D3 TIME MARK RTCINT MARKFB1 MARKFB2 D4 D5 VDD VSS D6 D7 WPROG NANDA NANDB TDO TCK TRST NANDOP TMS TDI MARKFB3 TDO7 DISCOP TDO6.