FireFly-1A GPS Disciplined Oscillator (GPSDO) Module
Compact, low-power GPS disciplined OCXO module that provides a 1 PPS output synchronized to UTC and a 10 MHz sine-wave reference output.
- 1 PPS Accuracy
- ±50 ns to UTC RMS (1-Sigma) GPS Locked
- Holdover Stability
- <±11 µs over 3 Hour Period
- 1 PPS Output (OCXO Flywheel Generated)
- 3.3 V DC CMOS
- RS-232 Control
- NMEA and SCPI-99 Control Commands
Overview
The VIAVI FireFly-1A is a very small Global Positioning System Disciplined Oscillator (GPSDO) with low power consumption. It is built for both mobile and stationary applications, and its long-term performance is comparable to that of atomic frequency standards.
When locked to GPS, the module achieves Stratum-1 long-term performance of better than 10 parts per trillion (1E-11) averaged over 24 hours. Its volume is 1.25 cubic inches, in a 1.0" x 2.5" x 0.5" form factor. The module generates an OCXO-driven 1 PPS output that is phase-synchronized to UTC, and a synchronized, low-noise 10 MHz sine-wave output.
The FireFly-1A is designed to be integrated into any application that needs a stable, accurate reference clock. It is monitored and controlled through an RS-232 port using NMEA and industry-standard SCPI commands. Two versions are available, a standard temperature option and an extended temperature option, each with SMB or SMA connector configurations. Firmware, GPSCon controller software and JLTerm terminal software can be downloaded for the module.
Key Features
- 1 minute warm up
- Small form factor of 1.0" x 2.5" x 0.5" (1.25 cubic inches)
- 72 Channel WAAS GPS Receiver
- Very low power consumption < 1.5 W, 1.4 W typical
- Stratum-1 long-term performance better than 1E-11 averaged over 24 hours when locked to GPS
- OCXO-driven 1 PPS output phase-synchronized to better than 100 ns rms to UTC
- Synchronized, low-noise +12 dBm, 10 MHz sine-wave output
- Monitoring and control via RS-232 using industry-standard SCPI commands
- Low phase noise, high spurious suppression and very low jitter
Specifications
| 1 PPS Accuracy |
±50 ns to UTC RMS (1-Sigma) GPS Locked
Web page states phase-synchronized to better than 100 ns rms to UTC; datasheet value given
|
|---|---|
| Holdover Stability |
<±11 µs over 3 Hour Period
@+25°C (No Motion)
|
| 1 PPS Output (OCXO Flywheel Generated) | 3.3 V DC CMOS |
| RS-232 Control |
NMEA and SCPI-99 Control Commands
1 PPS Level Output for Linux SNTP Server Software (with D Sub RTS pin)
|
| Avionics Support | 3D Velocity Vector (Velocity Output for the X, Y, and Z planes) |
| ADEV | 1 s – 1E-11 |
| TTL Alarm Output | GPS Unlock and Hardware Failure, and LOCK indicators |
| Warm Up Time/Stabilization Time |
<5 min to 1E-08 Accuracy
at +25°C
|
| GPS Frequency | L1, C/A 1574 MHz |
|---|---|
| GPS Antenna | Active or Passive |
| GPS Receiver |
50 Channels, Mobile, WAAS, EGNOS, MSAS capable
Web page and datasheet highlights state 72 Channel WAAS GPS Receiver; datasheet spec table value given
|
| Sensitivity, Acquisition | -144 dBm |
| Sensitivity, Tracking | -160 dBm |
| TTFF, Cold Start | <45 sec |
| TTFF, Warm Start | 1 sec |
| TTFF, Hot Start | 1 sec |
| Frequency Output | 10 MHz Sine Wave |
|---|---|
| 10MHz Retrace |
±2E-08 After 1 Hour
@ +25°C
|
|
Frequency Stability Over Temperature (Unlock Condition)
Standard Temperature Option
|
±2.5E-08 |
|
Frequency Stability Over Temperature (Unlock Condition)
Extended Temperature Option
|
±2.5E-07 |
| Output Amplitude |
+13 dBm ±3 dBm
Web page and datasheet overview describe a +12 dBm output; datasheet spec table value given
|
| Warm Up Time |
<1 min
@ +25°C
|
| 1 Hz | -80 dBc/Hz |
|---|---|
| 10 Hz | -110 dBc/Hz |
| 100 Hz | -135 dBc/Hz |
| 1 kHz | -145 dBc/Hz |
| 10 kHz | <-145 dBc/Hz |
| 1 PPS Output, 10 MHz Output |
SMB or SMA
See variant options
|
|---|---|
| RS-232 | 3 Pin |
| Supply Voltage (Vdd) | 8.0 V to 14.0 V DC (12 V DC Nominal) |
|---|---|
|
Power Consumption
Standard Temperature Option
|
<1.8 W Max, 1.35 W Typical
Web page states 1.4 W typically
|
|
Power Consumption
Extended Temperature Option
|
<2 W Max, 1.35 W Typ.
Web page states 1.4 W typically
|
|
Operating Temperature
Standard Temperature Option
|
0°C to +60°C |
|---|---|
|
Operating Temperature
Extended Temperature Option
|
-40°C to +75°C |
| Storage Temperature | -45°C to +85°C |
| Dimensions | 1.0" x 2.5" x 0.5" |
|---|---|
| Volume | 1.25 cubic inches |
Specifications are taken from the manufacturer's documentation. See the datasheet for complete and current values.
Applications
- Defense
- 5G Communications
- SATCOM
- Transportation
- Data Center
- Energy
- Financial
- Critical Infrastructure
- Mobile and stationary reference clock applications
Options & Accessories
| Option | Description |
|---|---|
| 100100-6V-G2 | FireFly-IA SOXCO Standard Temp 1PPS - RoHS |
| 100101-12V-G2 | FireFly-IA SOXCO Standard Temp SMA - RoHS |
| 100102-12V-G2 | FireFly-IA SOXCO Extended Temp - RoHS |
| 100107-6V-G2 | FireFly-IA SOCXO Extended Temp SMA -1PPS 1.2 - RoHS |
| 100152-12V-G2 | FireFly-IA SOXCO Extended Temp SMA - RoHS |