Microchip 5071A Datasheet

5071A

Primary Frequency Standard

Features

• Easy to use with automatic startup and

intuitive menu structure

• Fast warm up ±5.0 x 10

minutes or less for high-performance tube

• Integrated clock and message displays

• Multiple timing and frequency inputs and

outputs with easy access at front and rear

• Automatic synchronization of 1PPS signal

• Remote interface and control including

alarm output

• Meets requirements in the new ITU-T

G.811.1 ePRC standard

Benets

• Maintains exceptional accuracy and

stability even in unstable environments—

unsurpassed stability in the lab or eld

• Accuracy ±1.0 x 10

mance; ±5.0 x 10

• Stability ≤1.2 x 10

mance; ≤5.0 x 10

(for 1 second averaging time)

• Environmental stability ±1.0 x 10

standard performance; ±8.0 x 10
high performance (frequency change
for any combination of environmental
conditions)

• Long-term stability ≤5.0 x 10

dard performance; ≤1.0 x 10

performance (for 5-day averaging time)

• Proven reliability with an average mean

time between failures (MTBF) of greater
than 160,000 hours

• Full traceability to NIST

• AC and DC input and internal battery

back-up

–13

accuracy in 30

–12

for standard perfor-

–13

for high performance

–11

for standard perfor-

–12

for high performance

–13

for

–14

for

–14

for stan-

–14

for high

The 5071A primary frequency standard
has the accuracy and stability you need

for both laboratory and eld applications.
A stability specication for 30-day aver-

aging time means the 5071A will keep
extremely predictable time and phase
for long periods. Further, the 5071A can
be used for long-term averaging of noisy
signals such as GPS.

The 5071A is easy to use. No more
manual start-up steps or complicated
adjustments—everything is automatic.

A logical menu structure simplies front

panel operations, selections, and status
reporting. Remote control features tailor
the 5071A for complete operation and
manageability in virtually any location.

The instrument is a direct descendant of
and replacement for the veteran 5060A,
5061A, and 5061B cesium standards.
This innovative product is the result of
more than 35 years of experience in the
precision frequency standard business.

Frequency and Timing

Meeting the Needs of Leading­Edge Metrology and Calibration
Labs

Timekeeping and National Standards
Laboratories verify the stability and accu­racy of their in-house cesium standards
to Coordinated Universal Time (UTC),
provided by the Bureau International
des Poids et Mesures (BIPM) in Paris.
A standard’s accuracy and reliability
determine the quality of service these
timekeeping labs provide. Of even greater
concern is the stability of a standard.
Stability directly aects a laboratory’s abil­ity to deliver timekeeping and calibration
services to its clients.

The 5071A oers exceptional stability
and is the rst cesium standard to specify

its stability for averaging times longer
than one day. The instrument takes into
account environmental conditions that

can heavily inuence a cesium standard’s

long-term stability. Digital electronics
continuously monitor and optimize the
instrument’s operating parameters.

Thus, the 5071A’s response to environ­mental conditions such as temperature
and humidity are virtually eliminated.
The 5071A primary frequency standard
maintains its accuracy and stability, even
in unstable environments.

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Satellite Communications

Stable frequency generation is required to transmit and
receive signals properly between ground terminals and

communication satellites. Frequency exibility is also needed
to adjust for satellite-to-satellite carrier-frequency dierences.
The 5071A’s state-of-the-art technology produces oset and

primary frequencies with the same guaranteed stability.

Exceptional Accuracy

The intrinsic accuracy of the improved cesium beam tube
(CBT) assures that any high performance 5071A will power up
to within ±5.0 x 10
This is achieved under full environmental conditions in 30
minutes or less, and without the need for any adjustments or
alignments.

–13

of the accepted standard for frequency.

For secure communications, precise timing synchroniza­tion ensures that encrypted data can be recovered quickly.
Frequency-agile signals also require exact synchronization
between transmitter and receiver during channel hops.

The 5071A automates the synchronization to any external
1PPS signal, greatly simplifying this aspect of satellite
communications.

The 5071A and GPS

The 5071A primary frequency standard can work very well
with a GPS timing receiver to produce and maintain highly
accurate time and frequency.

The GPS system provides accurate time, frequency, and
location information worldwide by means of microwave radio
broadcasts from a system of satellites. Timing accuracy for
the GPS system is based, in large part, on the accuracy and
stability of a number of 5071A primary frequency standards.
These standards are maintained by the GPS system, the US
Naval Observatory, and various timing laboratories around the
world that contribute to UTC, the world time scale.

Because of their accurate time reference, GPS signals
processed by a good GPS timing receiver can provide highly
accurate time and frequency outputs. However, since GPS
receivers rely on very low level microwave signals from the
satellites, they sometimes lose accuracy because of interfering
signals, local antenna problems, or bad satellite data.

In spite of these problems, a GPS timing receiver can be an
excellent backup and reference to a local 5071A primary
frequency standard. The GPS receiver provides an indepen­dent reference that can be used to verify the accuracy of a
caesium standard, or it can be used as a temporary backup
should the cesium standard need repair. The local 5071A
standard has better stability, better output signal quality, and is
not perturbed by interfering signals, intermittent signal loss, or
bad satellite data.

With these characteristics, the synergy created by combin­ing a good quality GPS timing receiver and a 5071A primary
frequency standard can produce a highly robust, inexpensive,
and redundant frequency and time system.

Unsurpassed Stability

The 5071A high-performance cesium beam tube guarantees
stability to be better than 1.0 x 10

ve days or greater. The 5071A is the rst cesium standard

to specify stability for averaging times longer than 1.0 x 105
seconds (approximately one day).

The 5071A is also the rst cesium standard to specify and
guarantee a icker oor. Flicker oor is the point at which the
standard’s stability (σy (2, τ)) does not change with longer
averaging. The high performance 5071A icker oor is guar-

anteed to be 1.0 x 10

–14

or better. Long-term measurements

at the National Institute of Standards and Technology (NIST)

show that the icker oor is typically better than 5.0 x 10

Unstable environments are normal for many cesium standard
applications. The 5071A features a number of microproces­sor controlled servo loops which allow it to virtually ignore

changes in temperature, humidity, and magnetic elds.

The 5071A delivers exceptional performance over very long
periods of time, greatly increasing the availability of critical
time and frequency services. Actual measurements made
at NIST have demonstrated that a 5071A with the high­performance CBT will drift no more than 5.0 x 10
entire life of the CBT.

–14

for averaging times of

–14

over the

–15

.

Traditional Reliability

The 5071A has demonstrated an average mean time be­tween failures (MTBF) of greater than 160,000 hours since its

introduction in 1992. This data is based on actual eld repair

data. Backing up this reliability is a 10-year warranty on the
standard long-life cesium beam tube and a 5-year warranty
for the high performance tube.

Complete repair and maintenance services are available at our
repair center in Beverly, Massachusetts.

Full Traceability to NIST

Microchip provides NIST traceability to the accuracy measure­ments made on every 5071A. Traceability to NIST is maintained
through the NIST-supplied Time Measurement and Analysis
System (TMAS). This service exceeds the requirements of

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MIL-STD-45662A and can be a valuable tool in demonstrating
traceability to your customers.

Straightforward Operation

Internal microprocessor control makes start-up and operation of
the 5071A extremely simple. Once connected to an AC or DC
power source, the 5071A automatically powers up to its full accu-

racy specications. No adjustments or alignments are necessary

during power-up or operation for the life of the cesium tube.

An intuitive menu structure is accessible using the front panel
LCD display and keypad. These menus—Instrument State, Clock

Control, Instrument Conguration, Event Log, Frequency Oset

and Utilities—logically report status and facilitate control of the
instrument. These functions are described as follows.

Instrument State

Overall status is displayed, including any warnings in eect. Key
instrument parameters such as C-eld current, electron multiplier

voltage, ion pump current, and cesium beam tube oven voltage
are available. You can initiate a hard copy report of this data on
your printer with the push of a button.

Clock Control

Set the time and date, schedule leapseconds, adjust the epoch
time (in 50 ns steps), and automatically synchronize the 1PPS
signal to within 50 ns of an external pulse using this menu.

Instrument Conguration

Set the instrument mode (normal or standby) and assign fre­quencies (5 MHz or 10 MHz) to the two independently program-

mable output ports; congure the RS-232C data port.

High-Performance Cesium Beam Tube

The 5071A high performance cesium beam tube is optimal for
the most demanding operations. The high-performance tube

oers a full-environment accuracy specication of ±5.0 x 10

–13

—two times better than the specication for the standard tube.
Stability is also signicantly improved. The high-performance
tube reaches a icker oor of 1.0 x 10

–14

or better, and long-

term measurements at NIST show that the icker oor is

typically better than 5.0 x 10

–15

.

Integrated Systems and Remote Operation

Today, cesium standards are often integrated into telecom­munication, satellite communication, or navigation systems as
master clocks. To accommodate these environments, the 5071A
provides complete remote control and monitoring capabili­ties. Instrument functions and parameters can be interrogated
programmatically.

Communication is accomplished using the standard commands
for programmable instruments (SCPI) language and a dedicated
RS-232C port. Also, a rear panel logic output can be pro-

grammed to signal when user-dened abnormal conditions exist.

For uninterruptible system service, an internal battery provides
45 minutes of backup in case of AC power failure. Thus,
the 5071A can be managed easily even in the most remote
locations.

Event Log

Signicant internal events (power source changes, hardware

failures, warning conditions) are automatically recorded with the
time and date of their occurrence. A single keystroke produces a
hard copy on your printer for your records.

Frequency Oset (Settability)

Output frequencies may be oset by as much as 1.0 x 10–9

in steps of approximately 6.3 x 10

–15

. All product stability and

output specications apply to the oset frequency.

Utilities

The rmware revision level and cesium beam tube identication

information can be displayed.

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Specications

Electrical

Frequency Outputs (4)

[1] 100 kHz and

Frequency

Format

Amplitude

Harmonic

Non-harmonic

Connector

Load Impedance

Location

Isolation Between Ports

Timing Outputs (3) 1PPS

Format

Amplitude

Pulse Width

Rise Time

Jitter

Connector

Load Impedance

Location

Sync input

Amplitude

Pulse Width

Rise time

Jitter

Connector

Load Impedance

Location

Manual Sync

Range

Resolution

Auto Sync

1

Each output can be set to either 5 MHz or 10 MHz from the front panel or by remote control.

[2] 5 MHz, 10 MHz

Sine Sine

≥1 Vrms ≥1 Vrms

≤–40 dBc ≤–40 dBc

≤–80 dBc

N BNC

50 Ω 50 Ω

Rear panel Rear panel

≥110 dB (typical)

1PPS

≥2.4 V into 50 Ω (TTL compatible)

20 μs

≤5 ns (slew rate >10–9 volt/second at 1.5 V)

≤1 ns rms

BNC

50 Ω

One front panel

Two rear panel timing outputs

(2) 1PPS
(Each may be independently armed)

2 V—10 V max

100 ns min to 100 μs max

≤50 ns

≤1 ns rms

BNC

50 Ω

One front panel

One rear panel

+/–0.5 s

50 ns

+/–50 ns

1

[1] 1 MHz

General Environment

Temperature

Operating

Non-operating

Humidity

Magnetic Field

Atmospheric Pressure

Shock and Vibration

EMI/EMC

UL Safety

AC Power Requirements

Operating Voltage

Power

Operating

Warm-up

DC Power
Requirements

Power

Operating

Warm-up

Internal Standby Battery

Capacity

Charge Time

Charge source

Dimensions/weight

Height

Width

Depth

Weight

MTBF

0 °C—55 °C

–40 °C—70 °C

0 to 95% RH (45 °C max)

DC, 55, 60 Hz 2 gauss
Peak—Any Orientation

≤1.0 × 10

pressure down to 19 kPa (Equivalent to an
altitude of 12.2 km)

–13

change in frequency for

• Shipboard Vibration MIL-STD-167-1,

Paragraph 5.1.2.4.3

• Random Vibration MIL-PRF-28800F,

Paragraph 3.8.4.1 for Class 3 units (2.06
grms 5-500 Hz for 10 min/axis, 3 axes)

• Hammer Blow Shock Test, MIL-S-901C,

Grade A, Class 1, Type A

• Seismic Testing in accordance with

ASCE 7-10 Section 13.2.5. Will maintain
containment of Cesium metal (CAESIUM
UN1407) after testing to ICC-ES AC 156.

• FCC Part 15 Subpart B Class A

• KN61000-6-3 Radiated/Conducted

Emissions

• EN55011 Conducted Emissions

• KN/EN61000-3-2, -3 (AC)

• EN61000-4-4, -5, -6, -11

• KN61000-6-1 Immunity Tests

• KN61000-6-1, -3 (48VDC)

IEC 61010-1:2010 (Third Edition)

100, 120 VAC ±10%, 45 Hz—440 Hz

220, 240 VAC ±10%, 45 Hz—66 Hz

50 W (Standard Performance)

58 W (High Performance)

100 W

22 VDC—42 VDC

45 W (Standard Performance)

50 W (High Performance)

85 W

45 minutes from full charge

16 hours max from fully discharged state

AC input power supply

133.4 mm

425.5 mm

523.9 mm

30 kg

>160,000 hours

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Remote System Interface and Control

RS-232-C (DTE conguration)

Complete remote control and interrogation of all instrument
functions and parameters

Specication

Software
Command Set

Connector

Location

Alarm (TTL)

Output

Circuit is TTL open collector with internal pull-up resistor. Circuit can sink
up to 10 mA.

Standard Commands for Programmable
Instruments (SCPI), version 1990.0 adapted for
RS-232C

9-pin male rectangular D subminiature type

Rear panel

BNC

TTL High, Normal

TTL Low, Fault

Stability (Allan Deviation)

Average Time (s)

0.01 ≤7.5 × 10

0.1 ≤1.2 × 10

1 ≤1.2 × 10

10 ≤8.5 × 10

100 ≤2.7 × 10

1,000 ≤8.5 × 10

10,000 ≤2.7 × 10

100,000 ≤8.5 × 10

5 days ≤5.0 × 10

30 days ≤5.0 × 10

Flicker oor: Guaranteed

Typical

Standard
Performance

≤5.0 × 10

≤1.5 × 10

High Performance

–11

–11

–11

–12

–12

–13

–13

–14

–14

–14

–14

–14

≤7.5 × 10

≤1.2 × 10

≤5.0 × 10

≤3.5 × 10

≤8.5 × 10

≤2.7 × 10

≤8.5 × 10

≤2.7 × 10

≤1.0 × 10

≤1.0 × 10

≤1.0 × 10

≤5.0 × 10

–11

–11

–12

–12

–13

–13

–14

–14

–14

–14

–14

–15

Accuracy and Long-term Stability

2

Specication

Conditions (any combination of)

Temperature

Humidity

Magnetic Field

Shock and vibration

0 °C–50 °C

0 to 85% (40 °C max)

DC, 55, 60 Hz, 2G peak any orientation

100-mm drop

Accuracy

Standard performance

High performance

±1.0 × 10

±5.0 × 10

–12

–13

Frequency Change vs. Environment

Standard performance

High performance

Warm-up time (typical)

Reproducibility

±1.0 × 10

±8.0 × 10

30 minutes

±1.0 × 10

–13

–14

–13

Settability

Range

Resolution

Control

2

Lifetime accuracy (high performance CBT only) after a minimum two-month warm-up. Change no

more than 5.0 × 10

–14

for the life of the CBT.

±1.0 × 10

6.3 × 10

Through RS-232 port

–9

–15

SSB Phase Noise

Oset (Hz) 10 MHz Output 5 MHz Output

1 ≤–100 dBc/Hz ≤–106 dBc/Hz

10 ≤–130 dBc/Hz ≤–136 dBc/Hz

100 ≤–145 dBc/Hz ≤–145 dBc/Hz

1,000 ≤–150 dBc/Hz ≤–150 dBc/Hz

10,000 ≤–154 dBc/Hz ≤–154 dBc/Hz

100,000 ≤–154 dBc/Hz ≤–154 dBc/Hz

Ordering Information

Part Number Description

5071A-C001

5071A-C002

5071A-C007

5071A-C008

High-performance tube

Standard performance tube

High-performance tube with 48 VDC option

Standard performance tube with 48 VDC option

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companies.

© 2019, Microchip Technology Incorporated. All Rights Reserved. 4/19 900-00510-000 Rev J

DS00002980B

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