090-02984-007,090-02984-007 pdf中文资料,090-02984-007引脚图,090-02984-007电路-Datasheet-电子工程世界

文档预览

Frequency and Timing

SA.45s Space CSAC

Chip-Scale Atomic Clock

Features

•

Power consumption <120 mW

•

Less than 17 cc volume,

•

1.6" × 1.39" × 0.45"

Radiation-tolerant: 20 krad

SEL, SEU tested to 64 MeV-cm

/mg

(contact factory for details)

10 MHz CMOS-compatible output

1PPS output and 1PPS input for

synchronization

RS-232 interface for monitoring and

control

Short-term stability (Allan Deviation) of

3.0 × 10

–10

at TAU = 1 sec

Applications

•

Satellite timing and frequency control

•

Satellite clock reference

•

Assured Position, Navigation and

Timing (PNT)

•

Atomic clock accuracy

•

Satellite cross-linking

The Microchip SA.45s Commercial

Space Chip-Scale Atomic Clock's

(CSAC) potential for low size, weight,

and power (SWaP), and high timing

performance at relatively low cost

makes it very attractive for Low Earth

Orbit (LEO) applications. In addition to

being a stand-alone atomic clock with a

10 MHz output, the CSAC also has a

1PPS output and can be disciplined with

a 1PPS input. The Space CSAC retains

this functionality and is a timing module

that can be disciplined with a GPS-

derived 1PPS input.

The SA.45s provides 10 MHz and 1PPS

outputs at standard CMOS levels,

with short-term stability (Allan Deviation)

of 3.0 × 10

–10

at TAU = 1 sec, typical

long-term aging of <9 × 10

–10

/month,

and maximum frequency change of

±5 × 10

–10

over an operating temperature

range of –10 °C to 70 °C.

A standard CMOS-level RS-232 serial

interface is built into the SA.45s. This

is used to control and calibrate the unit

and to provide a comprehensive set of

status monitors. The interface is also

used to set and read the CSAC’s internal

time-of-day clock.

www.microchip.com

Specifications

Electrical

RF Outputs

Frequency

Format

Amplitude

Load Impedance

Quantity

1PPS Output

Rise/fall Time (10%–90%)

at Load Capacitance 10 pF

Pulse Width

Level

Logic High (V

) Min

Logic Low (V

) Max

Load Impedance

Quantity

1PPS Input

Format

Low Level

High Level

Load Impedance

Quantity

Serial Communications

Protocol

Format

Tx/Rx Impedance

Baud Rate

Format

Load Impedance

Logic

Power Input

Operating

Warmup

Input Voltage (V

)

Environmental

Specification

10 MHz

CMOS

0 V to V

1 MΩ

Operating Temperature

Details

–10 °C to 70 °C

Maximum Frequency Change

over Operating Temp Range

±5 × 10

–10

(Maximum Rate of Change

0.5 °C per Minute)

Frequency Change Over

Allowable Input Voltage

Range

Magnetic sensitivity

(≤2.0 Gauss)

Radiated Emissions

Vibration

Humidity

+/-4 × 10

-10

±9 × 10

–11

/Gauss

Compliant to FCC part 15, Class B,

when mounted properly onto host PCB

Maintains lock under MIL-STD-810G,

Operational, 7.7 g

rms

per Figure

514.7E-1. Category 24

0%–95% RH per MIL-STD-810,

Method 507.4

–55 °C to 85 °C

MIL-STD-810G, 7.7 g

rms

per Figure

514.7E-1. Category 24

MIL-STD-202-213A, Condition E,

1000 g

<10 ns

100 μs

0 V to V

2.80 V

0.30 V

1 MΩ

Rising edge

<0.5 V

2.5 V to V

1 MΩ

RS232

CMOS 0 V to V

1 MΩ

57600

CMOS 0 V to V

1 MΩ

0= Normal operation

1= Alarm

<120 mW

<140 mW

3.3 ± 0.1 V

Storage and Transport (Non-operating)

Temperature

Vibration

Shock

Performance Parameters

Specification

Warm-up Time

Analog Tuning

Details

<180 s

Range: ±2.2 × 10

–8

Resolution: 1 × 10

–11

Input: 0 V–2.5 V into 100 kΩ

Digital Tuning

Range: ±1 × 10

–6

Resolution: 1 × 10

–12

Built-In Test Equipment (BITE) Output

Phase Noise (SSB)

Frequency

1 Hz

10 Hz

100 Hz

1 kHz

10 kHz

100 kHz

Frequency Accuracy

Maximum Offset at Shipment

±5 × 10

–11

Maximum Retrace

(48 hrs Off)

1 PPS Sync

±5 × 10

–10

±100 ns

CSAC

<–50 dBc/Hz

<–70 dBc/Hz

<–113 dBc/Hz

<–128 dBc/Hz

<–135 dBc/Hz

<–140 dBc/Hz

At input voltage V

= 3.3 V

and ambient temperature = 25 °C, unless otherwise specified.

www.microchip.com

Aging

Type

Monthly

Yearly

SA.45s

<9 × 10

–10

<1 × 10

–8

Ordering Information

Part Number

090-02984-007

Description

Space chip-scale atomic clock

Output

Frequency

10 MHz

After 30 days of continuous operation.

All CSAC units are tested for aging specs as per the datasheet and meet the specs at the time

of shipment. However, continuous operation of CSAC over extended period of time may yield

unpredictable aging performance, resulting in failure to meet the aging specs and may not be

suitable for certain applications.

Short-Term Stability (Allan Deviation)

Type

τ=1s

τ = 10 s

τ = 100 s

τ = 1000 s

SA.45s

3 × 10

–10

1 × 10

–10

3 × 10

–11

1 × 10

–11

Radiation Tolerance

Type

TID

SEL, SEU

SA.45s

20 krad, <5 × 10

–10

frequency offset change

Tested to 64 MeV-cm

/mg

(contact factory for details)

Physical

Type

Weight

Size

MTBF

SA.45s

<35 g (<1.23 oz)

1.6" × 1.39" × 0.45"

>100,000 hours

Solder

Hand solder using 63/37 tin/lead solder with maximum

soldering tip of 329 °C (625 °F).

The Microchip name and logo and the Microchip logo are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. All other trademarks mentioned herein are property of their respective

companies.

DS00002982A

www.microchip.com