Dual SPM Detector

Page 9 of 16

MX641 Preliminary Information

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ã2001 MX-COM, Inc.

www.mxcom.com tel: 800 638 5577 336 744 5050 fax: 336 744 5054

Doc. # 20480115.004

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA

All trademarks and service marks are held by their respective companies.

4.3.1.1

Controlled Sensitivity Setting Information

The sensitivity figures in Table 4 are based on the following:

1.

The recommended amplifier components (see Figure 2) are used, providing an amplifier gain at 16kHz

of 19.8dB ±0.3dB or at 12kHz of 19.1dB ±0.3dB.

2.

A comparator sensitivity of 1.6dB(ref.) ±1dB (the variation is due to filter gain error, filter output offset,

comparator input offset or a combination of all 3).

3.

12kHz System

Bit D0 = ‘1’

16kHz System

Bit D0 = ‘0’

Serial Data

Bits

Bandpass

Filter Gain

Minimum

Sensitivity

Nominal

Sensitivit

y

Maximum

Sensitivity

Minimum

Sensitivity

Nominal

Sensitivit

y

Maximum

Sensitivity

D5 - D1

(dB)

dB(ref.)

dB(ref.)

dB(ref.)

dB(ref.)

dB(ref.)

dB(ref.)

00000

0

-16.2

-17.5

-18.8

-16.9

-18.2

-19.5

00001

1.0

-17.2

-18.5

-19.8

-17.9

-19.2

-20.5

00010

2.0

-18.2

-19.5

-20.8

-18.9

-20.2

-21.5

00011

3.0

-19.2

-20.5

-21.8

-19.9

-21.2

-22.5

00100

4.0

-20.2

-21.5

-22.8

-20.9

-22.2

-23.5

00101

5.0

-21.2

-22.5

-23.8

-21.9

-23.2

-24.5

00110

6.0

-22.2

-23.5

-24.8

-22.9

-24.2

-25.5

00111

7.0

-23.2

-24.5

-25.8

-23.9

-25.2

-26.5

01000

8.0

-24.2

-25.5

-26.8

-24.9

-26.2

-27.5

01001

9.0

-25.2

-26.5

-27.8

-25.9

-27.2

-28.5

01010

10.0

-26.2

-27.5

-28.8

-26.9

-28.2

-29.5

01011

11.0

-27.2

-28.5

-29.8

-27.9

-29.2

-30.5

01100

12.0

-28.2

-29.5

-30.8

-28.9

-30.2

-31.5

01101

13.0

-29.2

-30.5

-31.8

-29.9

-31.2

-32.5

01110

14.0

-30.2

-31.5

-32.8

-30.9

-32.2

-33.5

01111

15.0

-31.2

-32.5

-33.8

-31.9

-33.2

-34.5

10000

16.0

-32.2

-33.5

-34.8

-32.9

-34.2

-35.5

10001

17.0

-33.2

-34.5

-35.8

-33.9

-35.2

-36.5

10010

18.0

-34.2

-35.5

-36.8

-34.9

-36.2

-37.5

10011

19.0

-35.2

-36.5

-37.8

-35.9

-37.2

-38.5

10100

20.0

-36.2

-37.5

-38.8

-36.9

-38.2

-39.5

10101

21.0

-37.2

-38.5

-39.8

-37.9

-39.2

-40.5

10110

22.0

-38.2

-39.5

-40.8

-38.9

-40.2

-41.5

10111

23.0

-39.2

-40.5

-41.8

-39.9

-41.2

-42.5

11000

24.0

-40.2

-41.5

-42.8

-40.9

-42.2

-43.5

11001

25.0

-41.2

-42.5

-43.8

-41.9

-43.2

-44.5

11010

26.0

-42.2

-43.5

-44.8

-42.9

-44.2

-45.5

11011

27.0

-43.2

-44.5

-45.8

-43.9

-45.2

-46.5

11100

11101

11110

11111

These states should never be used. If sensitivities of this order are required (e.g. the Swedish Rural

SPM specification), it is recommended that the Controlled Sensitivity setting be set to 20dB (10100)

and external components selected to set the Input Amp gain to a higher figure. This action will

prevent falsing by sub-harmonic frequencies.

Table 4: Controlled Sensitivity Setting Information