SA605_15 Datasheet, PDF (11/25 Pages) NXP Semiconductors – High performance low power mixer FM IF system

NXP Semiconductors
SA605
High performance low power mixer FM IF system
RF GENERATOR⁽¹⁾
45 MHz
V_CC (+6 V)
SA605 DEMOBOARD
RSSI⁽²⁾
DC VOLTMETER
AUDIO
DATA
C-MESSAGE⁽³⁾
SCOPE
HP339A DISTORTION
ANALYZER⁽⁴⁾
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(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
SA605
Product data sheet
20
0
THD + NOISE
AM (80 % MOD)
NOISE
(dB) −20
RF = 45 MHz
IF = 455 kHz
V_CC = 6 V
AUDIO REF = 174 mV (RMS value)
−40
−60
RSSI (V)
−80
THD + NOISE
AM (80 % MOD)
NOISE
6
RSSI
(V)
5
4
3
2
1
−100
−130
−110
−90
−70
−50
−30
−10
RF input level (dBm)
Fig 6.
Audio out:
C message weighted
0 dB reference = recovered audio for 8 kHz peak deviation (dB)
Performance of the SA605 application board at 25 C
0
10 20
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All information provided in this document is subject to legal disclaimers.
Rev. 5 — 14 November 2014
© NXP Semiconductors N.V. 2014. All rights reserved.
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