SA605_15 Datasheet, PDF (9/25 Pages) NXP Semiconductors – High performance low power mixer FM IF system

NXP Semiconductors
11. Application information
SA605
High performance low power mixer FM IF system
FL1
C23
R17
5.1 kΩ
FL2
C21
C18 C17
20 19 18 17
16 15 14 13 12
IF amp
mixer
700 Ω
OSCILLATOR
limiter
RSSI
quad
detector
mute
switch
C15
11
12
34
5
6789
10
C3
C9
R9 R10 R11
R5(1)
C8
C1
L1
C2
C7
L2
C10 C11 C12 C13 _C26
C24
C25
L3
45 MHz
C5 C6
input
X1
C14
aaa-012965
The layout is very critical in the performance of the receiver. We highly recommend our demo
board layout.
All of the inductors, the quad tank, and their shield must be grounded. A 10 F to 15 F or higher
value tantalum capacitor on the supply line is essential. A low frequency ESR screening test on this
capacitor ensures consistent good sensitivity in production. A 0.1 F bypass capacitor on the
supply pin, and grounded near the 44.545 MHz oscillator improves sensitivity by 2 dB to 3 dB.
(1) R5 can be used to bias the oscillator transistor at a higher current for operation above 45 MHz.
Recommended value is 22 k, but should not be below 10 k.
Fig 4. SA605 45 MHz application circuit
SA605
Product data sheet
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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