1. GPSDO and Ruggedized Timing Products
Paul R. Gerry Senior Product Manager, Clocks BU

2. Agenda GPSDO Background Information
RCM Ultra Low Noise 10MHZ/100MHz Reference
OCXO Based GPSDOs
CSAC Based GPSDOs
Low Cost LTE-Lite GPSDOs

3. What Does a GPSDO Do?
GPS signals carry the Colorado NIST UTC master time- signal to the user. We decode this time signal, and generate a local version of it by controlling a local oscillator:

4. Why Use A GPSDO?
Primary frequency references like Cesium, Rubidium have drift
Temperature, g-sensitivity, C-field error, aging, relativistic effects
Free Running Oscillators: Synchronized
Frequency-Locked-Loop (poor phase coherence)
GPS Locked Oscillators: Synchronized
Phase-Locked-Loop (phase coherence to UTC)
Better than 5E-013/24Hrs possible with Quartz

5. In a GPSDO, the GPS Signal Provides…..
1PPS (pulse per second) within ~ ±25ns typ. of UTC
Independent of position
WAAS/EGNOS/MSAS error correction
PVT vector
Date/Time, down to the nanosecond level
Health information of Satellites
Major drawback:
Large sawtooth type jitter on the 1PPS
Outages are frequent, 1PPS missing occasionally
Foliage, Shading, Multipath induced errors

6. RCM Ultra Low Noise 100MHz, 10MHz, 1 PPS Reference Module

7. RCM Reference Holdover <+4us over 24-hrs typ.
Phase Noise of only -100dBc/Hz at 10Hz offset from the 100MHz carrier
Phase noise floor of -172dBc/Hz
Dual Frequency
One Ultra-stable 10MHz CMOS output, Two 100 MHz sinewave outputs
Allan Deviation of 1 sec
PPS signals have 2.5ns resolution
Supports external 10MHz or 1PPS signals reference inputs tight phase-lock to internal oscillators
Operating temperature range -40°C to +85°C

8. RCM Reference Applications
Radar Local oscillator for applications requiring ultra-low phase noise
Synchronized Radio applications
Phase-noise-filter applications for Rubidium or Cesium references

9. Ruggedized SSM-2650 -->SCM
Application: 24/7 search for any type of Communication to identify its Direction & Location
Key req: Ultra Extreme Sensitive & Accurate timing of the remote sensors to the C&C Center
Multiple remote Sensor units (1-N) which must be within 2 nsec diff from the Master Sync server
Ultra Low Phase Noise of: – 170dBc
Embedded VPX Sensor module
Rugged / MIL- STD

10. The “Standard / Commercial” offering
Remote Sync. & 100Mhz Ref. Clk.
XLi
GPS Signal Distribution
# MHz
#N 100MHz Sensor Sync. Embedded cards
vs. BC635’s
SSM Mhz Ref. board
#2 10MHz
#3 10MHz
#N 10MHz

11. RCM - 100MHz Phase Noise : SSM2650 option
RCM phase noise req.:
1 Hz <= -70 dBc
4 Hz <= -98 dBc
10 Hz <= -103 dBc
100 Hz <= -118 dBc
1 KHz <= -146 dBc
10 KHz <= -158 dBc
100 KHz <= -160 dBc
1 MHz <= -163 dBc
10 MHz <= -170 dBc
100 MHz <= -170 dBc
-163 dBc is nice…buy not meeting the spec. !

12. Microsemi & Focus’s - New Solution
New RCM design: Dual isolated 100MHz Ultra-Low Phase-Noise floor of -172dBc/Hz with +20.5dBm power . Allows external 10MHz or 1PPS signals to tightly phase-lock
ADEV of 2E-012 with low-g 100MHz osc. - phase-locked to the 10MHz DOCXO disciplined & provides 1PPS signals with 2.5ns resolution
Allowing 1PPS phase-locked to the 100MHz output even in the absence or failure of the external 1PPS or 10MHz references - for stand alone operation
This is on the Physics limit !!

13. RCM - Rugged VPX 1.1” Conduction Cooled Embedded Module
This application required the unit to be ruggedized to 167 & 810 MIL STD Embedded VPX module in Conduction cooled ATR Chassis
Customized packaging design for of the new RCM 100Mhz board
Rugged RCM VPX CC Module product !
Packaged as Rugged VPX module

14. RCM Ultra Low Noise Reference Module
2.0 X 4.0 X 1.0 In, ruggedized
1 PPS input to capture resolution of ±2.5 ns
Dual Frequency outputs
1 10 MHz 5V CMOS output
2 100 MHz sinewave outputs
Phase Noise (172dBc/Hz floor)
10MHz 100MHz
1Hz <-90dBc/Hz <-70dBc/Hz
10Hz <-125dBc/Hz <-98dBc/Hz
100Hz <-145dBc/Hz <-128dBc/Hz
1KHz <-150dBc/Hz <-153dBc/Hz
10kHz <-150dBc/Hz <-160dBc/Hz
100kHz <-150dBc/Hz <-165dBc/Hz
Ultra-low-g sensitivity (less than 0.3ppb per g per axis)
Operating Temperature range -40°C to +85°C

15. OCXO Based GPSDOs

16. GPS-1000 10Mhz OCXO-based GPSDO
Small 1.0” x 2.5” x 0.5” package
Holdover of ±11 µs over a 3-hr.
Compatible with GPS, WAAS, EGNOS, MSAS; Galileo-ready
1 PPS Accuracy of ±50 ns to UTC RMS (1-sigma), GPS-locked.
Output – 1 10 MHz output sinewave
Power consumption <1.4W typical
Phase Noise
1Hz -80dBc/Hz
10Hz -110dBc/Hz
100Hz -135dBc/Hz
1kHz -145dBc/Hz
10kHz <-145dBc/Hz
Operating Temperature range of 0° C to +60° C

17. GPS-2500/2550 DOCXO-based GPSDO
Small 1.5” x 3” x 0.8” package.
Holdover ±7 µs over 24-hr.
Compatible with GPS, WAAS, EGNOS, MSAS; Galileo-ready.
1 PPS Accuracy of ±50 ns to UTC RMS (1-sigma), GPS-locked.
Output MHz – 2 LVDS and 3 sinewave.
Phase noise
1Hz -80dBc/Hz
10Hz -110dBc/Hz
100Hz -135dBc/Hz
1kHz -145dBc/Hz
10kHz <-145dBc/Hz
Operating Temperature range of
0°C to +75°C; extended range of 25°C to +75°C available.

18. GPS-2600/2650 DOCXO-based GPSDO
1.5” x 4” x 0.8” package.
Holdover of ±7 µs over a 24-hr.
Compatible with GPS, WAAS, EGNOS, MSAS; Galileo-ready.
1 PPS Accuracy of ±30 ns to UTC RMS (1-sigma), GPS-locked.
Output 7 100Mhz - 2 sine, 4 LVDS, 1 CMOS; 2 10Mhz - 1 sine, 1 LVDS
Phase noise
1Hz -60dBc/Hz
10Hz -95dBc/Hz
100Hz -118dBc/Hz
1kHz -140dBc/Hz
10kHz -155dBc/Hz
100kHz -160dBz/Hz
Operating Temperature range of 0° C to +75° C; 25° C to +75° C available.

19. CSAC Based OCXOs

20. Benefits of a GPSDO module vs. a CSAC Component
CSAC total errors: ±2ppb (temp/age/gauss/cal etc)
GPS: << 0.2ppb within <20min
Module is plug-and-play, CSAC requires design-in
(system sale vs. component sale)
Phase Noise improvement: up to 13dB, >80% of spurs removed
Wider range of power supplies -- GPSDO can use vehicle power supply (8V to 36V) or USB; CSAC requires +3.3V.
Handling of common GPS anomalies and optimization for mission profile (Airborne, Vehicle, Manpack)

21. Additional Features -- Software Interface
Well known control interfaces (NMEA, SCPI, GPSCon, NTP etc)
Support for NMEA-0813 ver. 2.3 (Google Earth, etc)
USB Plug and Play, LCD driver built-in
Easy-to-use English commands, examples:
Help?
Syst:status?
GPS?, CSAC?

22. GPSDO with CSAC Compared GPSDO with OCXO Holdover?
CSAC Holdover after 20 minutes with GPS: typically better than 2us per day.
OCXO Holdover after 20 minutes with GPS: <13us over 4 hours (state of the art)
OCXO Holdover after 5 days with GPS: typically 1us to 2us per day. (SC-cut)
Confidential © Copyright 2011 19
Symmetricom Proprietary

23. GPSDO Benefits for Targeted Markets
•Manpack Systems:
Low power extends battery life.
Very fast warm-up (legacy products: 15+ min)
Very low-g while on move.
Airborne Systems:
Low phase noise under vibration
Wider temperature range than OCXO
Low SWaP and low profile
Stationary Systems:
Position and Hold mode
Holdover for up to 1 week
Long UPS life, independent of temperature

24. GPS 2700/2750
2” X 2.5” X 0.7” package
Holdover of ±1 µs over 24-hrs typ.
Compatible with GPS, WAAS, EGNOS, MSAS
1 PPS Accuracy of ±15 ns to UTC RMS (1-sigma), GPS-locked.
Outputs MHz Sinewave; 1 5MHz CMOS 5V
Power <1.5W, <1W CMOS option
Phase Noise
10Hz -75dBc/Hz
100Hz -115dBc/Hz
1KHz -128dBc/Hz
10kHz -134dBc/Hz
100kHz -140dBc/Hz
Operating Temperature range of
-10ºC to +70ºC

25. HD-CSAC 2” X 2.5” X 0.7” package Holdover of ±1 µs over 24-hrs typ.
Compatible with GPS, WAAS, EGNOS, MSAS
1 PPS Accuracy of ±15 ns to UTC RMS (1-sigma), GPS-locked.
Outputs MHz LVDS and 1 10MHz CMOS 5V
Power <1.25W
Phase Noise
10Hz -75dBc/Hz
100Hz -115dBc/Hz
1KHz -128dBc/Hz
10kHz -134dBc/Hz
100kHz -140dBc/Hz
Operating Temperature range of
-10ºC to +70ºC.

26. LP-CSAC 2” X 2.5” X 0.7” package Holdover of ±1 µs over 24-hrs typ.
Compatible with GPS, WAAS, EGNOS, MSAS
1 PPS Accuracy of ±15 ns to UTC RMS (1-sigma), GPS-locked.
Outputs MHz LVDS and 1 10MHz CMOS 3.3V
Power - <0.55 W
Phase noise
10Hz -75dBc/Hz
100Hz -115dBc/Hz
1KHz -128dBc/Hz
10kHz -134dBc/Hz
100kHz -140dBc/Hz
Operating Temperature range of 10° C to +70° C

27. LTE-Lite TCXO Based GPSDOs
Low-cost Small-Cell Frequency and Timing Reference

28. LTE-Lite 19.2 MHz 0.7” x 1.18” x 0.09” package.
<±50us over 3 Hour Period (25°C)
Compatible with, QZSS, SBAS WAAS, EGNOS, MSAS
Outputs MHz CMOS; 1 PLL synthesized configurable
76.8/38.4/25.6/15.36/12.8/9.6/4.8 MHz
Phase Noise (noise floor <155dBc/Hz)
1Hz -65dBc/Hz
10Hz -92dBc/Hz
100Hz -116dBc/Hz
1kHz -136dBc/Hz
10kHz -148dBc/Hz
100KHz <-155dBc/Hz
Operating Temperature -10°C to +70°C, -40°C to +85°C optional

29. LTE-Lite 20 MHz 0.7” x 1.18” x 0.09” package.
<±50us over 3 Hour Period (25°C)
Compatible with, QZSS, SBAS WAAS, EGNOS, MSAS
Outputs MHz CMOS; 1 PLL synthesized configurable
80/40/26.666/16/13.333/10/5 MHz
Phase Noise (noise floor <155dBc/Hz)
1Hz -65dBc/Hz
10Hz -92dBc/Hz
100Hz -116dBc/Hz
1kHz -136dBc/Hz
10kHz -148dBc/Hz
100KHz <-155dBc/Hz
Operating Temperature -10°C to +70°C, -40°C to +85°C optional

30. The GPSDO Demo Kit
The GPSDO demo kit allows you to easily demonstrate the usefulness of a board-level GPSDO to your customer base.
TCXO-based to hold down costs, so not “state of the art” holdover performance!
USB interface for demo convenience.
Demo Kit Contents:
Board with USB interface & cable
Antenna with cable
Documentation: CDROM, Read-me sheet

31. GPSDO Comparison OCXO CSAC <1.4W <3.2W <4W <0.55W 1.0E-11
Product
GPS-1000
GPS-2000
GPS-2500
GPS-2550
GPS-2600 GPS-2650
GPS-2700
GPS-2750
CSAC-LP
Technology
OCXO
CSAC
Size
1.0 x 2.5 x 0.5 in
1.5 x 3 x 0.65 in
1.5 x 3 x 0.8 in
1.5 x 4 x 0.8 in
2.5 x 3 x 0.7 in
2.0 X 2.5 X 0.7 in
Temp range
0°C to 60°C
0°C to 75°C
-25°C to 75°C
-10°C to 70°C
-10ºC to 70ºC
Power 25°C
<1.4W
<3.2W
<4W
<0.55W
ADEV 1s
1.0E-11
with GPS Lock
<6.0E-11
<1.0E-11
<1.0E-10
<1E-10
Phase Noise
10Hz
-110dBc/Hz
-120dBc/Hz
-95dBc/Hz
-75dBc/Hz
Holdover
<+ 11 uS
3 hours
<+ 60 uS
24 hours
<+ 7 uS
<+7 uS
<+ 2 uS
24 hour
Outputs
1 PPS
10 MHz
2 & 10 MHz
1 GHZ
10 MHZ
100 MHz
GPS L1
C/A 1574 MHz
C/A 1574MHz

32. Thank You Ramki Ramakrishnan Director of Marketing, Clocks BU
Paul R. Gerry Senior Product Manager, Clocks BU
Steve Fossi VP and General Manager, Clocks BU