VIAVI Mini-PCIe GPSDO GPS Disciplined Oscillator Module with 20 MHz and 1 PPS Outputs

Mini-PCIe GPS disciplined oscillator module with a 65-channel GPS receiver, a 20 MHz low phase noise output and 1 PPS timing for embedded systems.

1 PPS Timing Accuracy from GPS receiver: <10 ns to UTC RMS (1-Sigma)
Holdover Stability (1 week with GPS): <±50 µs over 3 Hour Period
1 PPS Output: 3.3 V DC CMOS, as well as on DCD# pin of COM port for NTP/1588
Serial Port: COM Port, NMEA Output with Oscillator Status/Health sentence

Datasheet

Overview

The VIAVI Mini-PCIe GPS Disciplined Oscillator (GPSDO) is a frequency and timing module built in the industry-standard Mini-PCIe form factor. It provides nanosecond timing for NTP, SNTP, GPSD, PTP/1588 and other standard timing applications, along with a low phase noise 20 MHz output. Typical uses include financial transaction time stamping and other applications that need a precise timing, frequency and position reference.

The module combines a 65-channel GPS receiver with WAAS, QZSS and SBAS support, filtered power supplies and a software-disciplined crystal oscillator. It uses analog crystal disciplining, which sets the phase noise, Allan Deviation (ADEV) and jitter performance of the on-board 20 MHz and 1 PPS CMOS outputs.

VIAVI specifies typical frequency accuracy better than 1 ppb and average timing accuracy better than 10 ns. The module can be built into servers, embedded PCs, tablets and notebook computers. It can also connect to any computer over a standard USB cable through a Mini-PCIe to USB adaptor.

Compatibility and software

The module works with all full-length Mini-PCIe connectors that support the standard USB function. Its integrated USB capability also lets it work with Mini-SSD mSATA connectors. VIAVI provides GPSCon controller software, GPSD firmware and JLTerm terminal software for configuring and monitoring the module.

Key Features

Mini-PCIe form factor
20 MHz, 1 PPS and LOCK-OK outputs
Integrated 65-channel GPS receiver with WAAS, QZSS and SBAS support
Built-in USB interface
Analog crystal disciplining for low phase noise, ADEV and jitter on the 20 MHz and 1 PPS CMOS outputs
Better than 1 ppb frequency accuracy (typical)
Better than 10 ns timing accuracy (average)
Compatible with all full-length Mini-PCIe connectors that support the standard USB function
Compatible with Mini-SSD mSATA connectors through the integrated USB capability
Connects to a standard USB port through an adaptor

Specifications

Module Specifications

1 PPS Timing Accuracy from GPS receiver	<10 ns to UTC RMS (1-Sigma) GPS Locked
Holdover Stability (1 week with GPS)	<±50 µs over 3 Hour Period @+25°C (No Motion, No Airflow)
1 PPS Output	3.3 V DC CMOS, as well as on DCD# pin of COM port for NTP/1588
Serial Port	COM Port, NMEA Output with Oscillator Status/Health sentence
TTL Alarm Output	CMOS LOCK indicator, LOCK LED
Warm Up Time/Stabilization Time	<10 min at +25°C to better than 1E-09 Accuracy
ADEV 10 s	<7E-011
ADEV 10K s	<2E-012 GPS Locked, 25°C, no motion, no airflow

GPS Receiver

GPS Frequency	L1, C/A 1574 MHz
GPS Antenna	Active or Passive (0 dB to +30 dB gain)
GPS Receiver	65 Channels, QZSS, SBAS WAAS, EGNOS, MSAS capable
Sensitivity, Acquisition	-148 dBm
Sensitivity, Tracking	-165 dBm
GPS TTFF, Cold Start	<32 sec
GPS TTFF, Warm Start	1 sec
GPS TTFF, Hot Start	1 sec

Oscillator Specifications

Frequency Output of Low Phase Noise Crystal	20 MHz CMOS 3 Vpp on U.Fl coax connector
Optional Synthesized CMOS output (Phase-Locked to 20 MHz)	80 MHz/40 MHz/26.666 MHz/16 MHz/13.333 MHz/10 MHz/5 MHz Resistor-Stuffing selectable
20 MHz Retrace	±2E-08 After 1 Hour @ +25°C without GPS
Frequency Stability Over Temperature (0°C to +60°C)	±100 ppb without GPS
RF Output Amplitude	3 Vpp CMOS
20 MHz Phase Jitter (100 Hz to 10 MHz)	<0.135 ps RMS
Frequency accuracy	better than one part per billion (1 ppb) Typical, per the product page
Timing accuracy	better than 10 nanoseconds On average, per the product page

Phase Noise (10 MHz TCXO)

1 Hz	<-68 dBc/Hz
10 Hz	<-98 dBc/Hz
100 Hz	<-122 dBc/Hz
1 kHz	<-142 dBc/Hz
10 kHz	<-152 dBc/Hz
100 kHz	<-155 dBc/Hz

Synthesized Output Frequencies (FREQ_SEL, 20 MHz default)

FREQ_SEL 111	disabled Configured via resistor stuffing options on the RF U.Fl coax connector
FREQ_SEL 110	5 MHz
FREQ_SEL 101	10 MHz
FREQ_SEL 100	13.33333333 MHz
FREQ_SEL 011	16 MHz
FREQ_SEL 010	26.66666667 MHz
FREQ_SEL 001	40 MHz
FREQ_SEL 000	80 MHz

Connections

Connections	1 PPS CMOS Output, 20 MHz CMOS Output, LOCK-OK CMOS Output, power, USB, antenna input
Connections Type	Mini-PCIe standard (USB interface), U.Fl coaxial
Additional Features	Can be connected to standard USB port via adaptor, U.Fl coax connectors for 1 PPS/20 MHz/LOCK-OK/GPS antenna

Power and Environmental

Supply Voltage (Vdd)	3.3 Single-Supply, +0.2 V/-0.15 V Via Mini-PCIe connector
Power Consumption	<0.2 W
Operating Temperature	-10°C to +70°C -40°C to +85°C optional