SA605

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© NXP Semiconductors N.V. 2014. All rights reserved.

Product data sheet

Rev. 5 — 14 November 2014

11 of 25

NXP Semiconductors

SA605

High performance low power mixer FM IF system

(1) The C-message filter has a peak gain of 100 dB for accurate measurements. Without the gain, the

measurements may be affected by the noise of the scope and HP339 analyzer.

(2) Set your RF generator at 45.000 MHz, use a 1 kHz modulation frequency and a 6 kHz deviation if

you use 16 kHz filters, or 8 kHz if you use 30 kHz filters.

(3) The smallest RSSI voltage (that is, when no RF input is present and the input is terminated) is a

measure of the quality of the layout and design. If the lowest RSSI voltage is 250 mV or higher, it

means that the receiver is in regenerative mode. In that case, the receiver sensitivity is worse than

expected.

(4) The measured typical sensitivity for 12 dB SINAD should be 0.22

V or 120 dBm at the RF input.

Fig 5.

SA605 application circuit test setup

Audio out:

C message weighted

0 dB reference = recovered audio for 8 kHz peak deviation (dB)

Fig 6.

Performance of the SA605 application board at 25

C

SCOPE

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45 MHz

DC VOLTMETER

HP339A DISTORTION

AUDIO

DATA

AUDIO REF = 174 mV (RMS value)

RSSI (V)

THD + NOISE

NOISE

AM (80 % MOD)

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−130

−80

2

3

4

−60

−40

−20

(dB)

NOISE

AM (80 % MOD)

THD + NOISE

RSSI

(V)

−110

−70

−50

−30

−10

RF input level (dBm)

0

−100

20

0

1

5

6

−90

10

20

RF = 45 MHz

IF = 455 kHz