ADSST-GPSRF01_15 Datasheet, PDF (1/16 Pages) Analog Devices – GPS RF Downconverter

FEATURES
Single chip GPS downconverter
GPS L1 band C/A code (1575.42 MHz) receiver
2.7 V to 3.3 V power supply
On-chip LNA
On-chip PLL including complete VCO
On-chip reference oscillator
On-chip NCO for sampling clock
Option to choose 6.144 MHz, or 6.552 MHz, or external
sampling clock
60 dB AGC dynamic range
SIGN and MAGN outputs
Low power operation 55 mA
Supports power-down mode
APPLICATIONS
Security applications
Asset tracking
Marine navigation
Portable GPS receiver
GPS RF Downconverter
ADSST-GPSRF01
GENERAL DESCRIPTION
The ADSST-GPSRF01 is a high performance, fully integrated,
RF front-end chip for downconversion and amplification of
GPS signals. It has been designed for L1 (1575.42 MHz), C/A
GPS band receivers.
The ADSST-GPSRF01 is a dual conversion, superheterodyne
receiver with an on-chip low noise amplifier (LNA), local oscil-
lator, two downconversion IF stages (at 24.52 MHz and 8.194 MHz,
respectively), an automatic gain controlled amplifier (AGC), and
a 2-bit analog-to-digital converter (ADC).
Two selectable, fixed frequency sampling clocks from an on-chip
NCO can be used for output sampling (6.144 MHz or 6.552 MHz).
In addition, an external sampling clock can be used up to 32 MHz.
The chip can be interfaced with any active/passive GPS antenna.
FUNCTIONAL BLOCK DIAGRAM
1575.42MHz
24.52MHz
8.194MHz
1575.42MHz
LNA
1550.9MHz
MIXER1
IF1
DIV 2
ON/OFF
VCO
CH PUMP
DIV 5
MIXER2
ADC
IF2
CMDPHI 0:6.552MHz
CMDPHI 1:6.144MHz
DIV 2 PF DETECTOR
16.3252910MHz
QUARTZ
DIV 19 DIV 4
NCO
0
1
CMDPHI CKIN CMDCKADC
Figure 1.
MAGN
SIGN
CKOUT
Rev. 0
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