SA604A_15 Datasheet, PDF (11/31 Pages) NXP Semiconductors – High-performance low-power FM IF system

NXP Semiconductors
SA604A
High-performance low-power FM IF system
SA604A IF INPUT (μV) (1500 Ω)
10
100
1k
10 k
100 k
0
THD + NOISE
AM (80 % MOD)
NOISE
(dB)
−20
AUDIO
RSSI (VOLTS)
THD + NOISE
−40
−60
AM (80 % MOD)
−80
NOISE
RSSI
(V)
4
3
2
1
−120
−100
−80
−60
−40
SA602A RF INPUT (dBm) (50 Ω)
−20
aaa-012849
Audio output: C message weighted; 0 dB reference = recovered audio for 8 kHz peak deviation (dB)
Fig 7. Performance of the typical cellular radio application
13.1 Circuit description
The SA604A is a very high gain, high frequency device. Correct operation is not possible
if good RF layout and gain stage practices are not used. The SA604A cannot be
evaluated independent of circuit, components, and board layout. A physical layout which
correlates to the electrical limits is shown in Figure 17. This configuration can be used as
the basis for production layout.
The SA604A is an IF signal processing system suitable for IF frequencies as high as
21.4 MHz. The device consists of two limiting amplifiers, quadrature detector, direct audio
output, muted audio output, and signal strength indicator (with log output characteristic).
The equivalent circuit is shown in Figure 4.
Figure 7 is the performance of the typical cellular radio application shown in Figure 6 with
45 MHz RF input and 455 kHz IF.
SA604A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 4.1 — 30 March 2015
© NXP Semiconductors N.V. 2015. All rights reserved.
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