QEM77-AH

41 x 41 mm / 19 pins

MCXO

Operating Procedure

SALES OFFICES:

Benelux: +33 (0) 1 49 88 49 00 / Germany: +49 (0)

89 820 796-27

/ Nordic: +46 (0) 8 59030300

France: +33 (0) 1 49 88 49 00 / Italy: +39 (0) 738 8869 / Spain: +33 (0) 1 49 88 49 00 / UK: +44 (0) 1256 883340

USA: +1 (623) 780-1995 / Asia-Pacific : +33 (0) 5 56 46 66 84

WEB SITE: http://www.temex-components.com

Specifications are subject to change without notice - Page 1 / 1

TEMEX

TIME &

FREQUENCY

QEM77AH
15-06-2000

Frequency Range :

Applications :

5 MHz to 16 Mhz Synchronisation System

Test equipment

Military Radio

Low Power Equipment

Description :

The MCXO offers the parameters of OCXO's and TCXO's, delivering practically the frequency of an ovenized oscillator with

the power consumption associated with temperature compensated oscillators over the entire military range of -55°C to +125°C.

Using digital techniques, it is possible to operate a stand-by mode with low power consumption and to synchronise the 1 Hz

signal with an external source. In addition, a choice of output frequency is available.

Control of Secondary functions :

The secondary functions of the MCXO are obtained by two methods :

application of logic levels on the pin-out as indicated

inputting bytes on the RS232 port.

The details of the logic controls are shown on the following pages.

Block-Diagram :

PD4

VPP6

FDDSI

IRQ

RESET

PC7

CTRL

FM2 (1 Hz input)

FM1 (1 Hz output)

Microcontroller

1 Hz synch.

/ 3

PLL

digital direct

synthesis

delta

dual-mode

oscillator

Vcc Gnd

supply voltage

stabilisation

Counter

A /D converter

RS 232 out

PD1

PD6

PD2

PD7

RS 232 in

PD5
(synch enable)

FMCXO
1, 5 or 10 MHz

QEM77-AH

41 x 41 mm / 19 pins

MCXO

Operating Procedure

SALES OFFICES:

Benelux: +33 (0) 1 49 88 49 00 / Germany: +49 (0)

89 820 796-27

/ Nordic: +46 (0) 8 59030300

France: +33 (0) 1 49 88 49 00 / Italy: +39 (0) 738 8869 / Spain: +33 (0) 1 49 88 49 00 / UK: +44 (0) 1256 883340

USA: +1 (623) 780-1995 / Asia-Pacific : +33 (0) 5 56 46 66 84

WEB SITE: http://www.temex-components.com

Specifications are subject to change without notice - Page 2 / 2

TEMEX

TIME &

FREQUENCY

QEM77AH
15-06-2000

Typical value for 10 Mhz

output frequencies

FMCXO outputs: 10 Mhz, 5 Mhz, 1Mhz user-selectable by external digital control FM1output 1

frequency variations vs.

Code FT 28

± 2 x 10

-8

from -30°C to +85°C

temperature changes

Code AY 17

± 1 x 10

-7

from -55°C to +125°C

Calibration precision

Nominal frequency settability (see below) at + 125°C attained for

1.4 V 1% on pin 18

short-term stability

2x10

-8

/ 1s. and 2x10

-8

/ 10s

long-term stability

1x10

-9

/ day and 1x10

-8

/ month

frequency stability vs
supply voltage

1.10

-9

( Vcc

5% )

vs load

1.10

-9

(between 1 LSTTL (gage) and 2 LSTTL (1 gage - 1 gate)

supply voltage

3.25 V

Vcc

6 V

input current

Start-up

6 mA

normal operation mode :

5 mA

stand-by mode :

4 mA

output levels

0.4 V and

2.4 V

output current FMCXO

0.5 mA

rise / fall time

20 ns between 20 % and 80 % of the actual output level, at +25°C

2°C

duty cycle

50 / 50 ± 5% at Vcc/2

frequency adjustement

1x 10

-5

(settability to 4.10

-9

)

on 10 Mhz

Potentiometer 47 k

between pin 18 and GND or

control voltage 0 to 3 V on pin 18 (slope 1 x 10

-6

/ V)

delay between adjustment and corresponding change of FMCXO :

500s to 4.10

-9

500 s to 1.10

-7

secondary functions

see next page

shock test

MIL STD 202F, method 213B, condition l : 3 x 3 shocks 100 g, sawtooth, 6 ms

vibration test (sinewave)

MIL STD 202F, method 204D, condition D : 10 Hz to 2 kHz / 10g / 3 axes

vibration test (random)

on request

package

n° 77

marking

QEM 77-AH + CQE+date code+serial number

QEM77-AH

41 x 41 mm / 19 pins

MCXO

Operating Procedure

SALES OFFICES:

Benelux: +33 (0) 1 49 88 49 00 / Germany: +49 (0)

89 820 796-27

/ Nordic: +46 (0) 8 59030300

France: +33 (0) 1 49 88 49 00 / Italy: +39 (0) 738 8869 / Spain: +33 (0) 1 49 88 49 00 / UK: +44 (0) 1256 883340

USA: +1 (623) 780-1995 / Asia-Pacific : +33 (0) 5 56 46 66 84

WEB SITE: http://www.temex-components.com

Specifications are subject to change without notice - Page 3 / 3

TEMEX

TIME &

FREQUENCY

QEM77AH
15-06-2000

Secundary functions

Logic levels

on dedicated inputs

Byte value

on pin 13

RS232 port

Action

delay

Result

PD1=

and PD2 =

$EF

FMCXO = 10 MHz

Output frequency

selection (FMCXO)

PD1=

and PD2 =

$EF

FMCXO = 5MHz

PD1=

and PD2 =

$FD

300 ms

FMCXO = 1MHz

PD1=

and PD2 =

Synchronisation

of FM1 on FM2

PD5 =

$FC

synch enable

PD5=

$CF

synch disable

Switching between normal

and

PD6 =

$CA

disable

stand-by modes

PD6=

$AC

enable

Phase measurement

PD7 =

n.a.

disable

(FM1, FM2)

PD7 =

n.a.

enable

$BF

increases FMCXO by 1 ppm

$FB

decreases FMCXO by 1ppm

$AB+3 bytes 300 ms

acquisition

time

increases FMCXO

proportionally to the 3 bytes

following $AB

Digital frequency

adjustment

through RS232 port

(see next page)

$BA+3 bytes

decreases FMCXO

proportionally to the 3 bytes

following $BA

$BC+3 bytes

adds a positive frequency offset to FMCXO

proportional to the 3 bytes following $BC

$CB+3 bytes

adds a negative frequency offset to FMCXO

proportional to the 3 bytes following $BC

$BD

cancels every software change, except those

performed by $BC or $CB

$BB

returns FMCXO to factory setting

Important notice

: It is recommanded that any action initiated through a dedicated input modified or cancelled by an other

action on a dedicated input. The same is true for commands issued on the RS232 port.

QEM77-AH

41 x 41 mm / 19 pins

MCXO

Operating Procedure

SALES OFFICES:

Benelux: +33 (0) 1 49 88 49 00 / Germany: +49 (0)

89 820 796-27

/ Nordic: +46 (0) 8 59030300

France: +33 (0) 1 49 88 49 00 / Italy: +39 (0) 738 8869 / Spain: +33 (0) 1 49 88 49 00 / UK: +44 (0) 1256 883340

USA: +1 (623) 780-1995 / Asia-Pacific : +33 (0) 5 56 46 66 84

WEB SITE: http://www.temex-components.com

Specifications are subject to change without notice - Page 4 / 4

TEMEX

TIME &

FREQUENCY

QEM77AH
15-06-2000

Synchronisation of FM

The 1 Hz frequency output on FM1 is derived by division of the 10 Mhz FMCXO, it has therefore the same relative

stability. In order to provide the function of a 1 pps generator in time keeping applictions, the FM1 output can be

synchronised with an external 1 Hz source. In this case, the synchronisation is effected between two positive-going edges

of the compared signals after applying the synchronisation validation signal. The maximum error between the two signals is

(Warning ! Synchronisation is not possible when the oscillator is in stand-by mode).

After synchronisation and switching to stand-by mode, an additional error inferior to

s is introduced.

Synchronisation on PDS by rising front.

Phase measurement

This function provides the means to measure the difference between rising fronts at 1 Hz on FM1 and FM2 with a precision

1 % or

s (whichever is the greater). During phase measurement, temperature compensation of the frequency

cannot be effected. It is therefore important that the temperature remains constant.

The result of this measurement is given by the RS232 link in the form of 3 bytes, the first of which is the most

significant. The phase-offset value on 10 Mhz is given by

offset (

s) = decimal value of the 3 bytes.

Stand-by mode (reduced power consumption)

In stand-by mode, the temperature compensation intervals are increased. This means the frequency precision is attained

after a longer stabilisation time. In this mode, only the 1 Hz-ouput is available. The dividing stages and certain other

functions are switched-off, thereby reducing the consumption to 4 mA.

RS232 Port Communication parameters

Format : NRZ

Speed : 2400 bits/s.

1 start bit/1 stop bit/8 data bits

no parity

logic levels : HCMOS 3 V

N.B. : the pin-outs 1, 3, 8, 17, 19 are used for initial setting during manufacture. They must not be connected, any connection

can either cause malfunctioning or cause permanent damage.

Digital frequency adjustment

Adjustments effected by means of the RS 232 port differ in their hierarchy : $BF, $FB, $AB, $BA, change temporarily the

FMCXO and can be cancelled by $BD or by $BB. Factory setting while $BB returns FMCXO to its original value.

Inputting $BC OR £CB superimposes an additional frequency offset that can only be cancelled by $BB.

Amplitude of the frequency adjustment is limited to

100 Hz

Computing the 3 correcting bytes (low, medium, high) :

value in Hex = Hex(Int(26.948 x

F(Hz)))

QEM77-AH

41 x 41 mm / 19 pins

MCXO

Operating Procedure

SALES OFFICES:

Benelux: +33 (0) 1 49 88 49 00 / Germany: +49 (0)

89 820 796-27

/ Nordic: +46 (0) 8 59030300

France: +33 (0) 1 49 88 49 00 / Italy: +39 (0) 738 8869 / Spain: +33 (0) 1 49 88 49 00 / UK: +44 (0) 1256 883340

USA: +1 (623) 780-1995 / Asia-Pacific : +33 (0) 5 56 46 66 84

WEB SITE: http://www.temex-components.com

Specifications are subject to change without notice - Page 5 / 5

TEMEX

TIME &

FREQUENCY

QEM77AH
15-06-2000

example :

F = 35 Hz gives $AF $03 $00

for 10 Mhz

for other frequency 1ppm = 270 (decimal) = $1E$01$00

Pin function

Pin #

Symbol

Typical signal

Maximum absolute rating

reserved for initial setting, don't connect 1

FDDSI

n.a.

1 Hz output

FM1

LS-TTL-compatible

0.4 V

2.4 V

sink/source 0.5 mA/10 pF

-0.5 V

3.2 V

reserved for initial setting, don't connect 3

VPP6

n.a.

1 Mhz, 5 Mhz or 10 Mhz

frequency output

4 FMCXO LS-TTL-compatible

0.4 V

2.4 V

sink/source 0.5 mA/10 pF

-0.5 V

3.2 V

1 Hz reference signal input

FM2

output frequency programming inputs

PD1

HCMOS 3 V

-0.5 V

6 V

PD2

reserved for initial setting, don't connect 8

PD4

n.a.

1 Hz synch enable / disable

PD5

stand-by / normal mode

PD6

HCMOS 3 V

-0.5 V

6 V

-measurement enable/disable

PD7

power supply

+3.2 V

+6 V

RS 232 input

RDI

HCMOS 3 V

-0.5 V

+6 V

RS 232 output

TDO

-0.5 V

out

+3 V

GND

0 V

n.a.

reserved for initial setting, don't connect 16 RESET

n.a.

PC7

frequency adjustment (analogue)

CTRL -0.5 V

CTRL

2.8 V

0 V

CTRL

3.5 V

reserved for initial setting, don't connect 19

IRQ

n.a.

Important notice

: the pins reserved for initial setting not be connected. Any connection could cause

malfunctioning or even permanent damage.

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