SA58640 NXP Semiconductors, SA58640 Datasheet - Page 9

• Manufacturer Part Number: SA58640
• Description: Low-voltage mixer FM IF system
• Manufacturer: NXP Semiconductors

Philips Semiconductors
13. Test information
9397 750 14161
Objective data sheet
The following list items
1. The C-message and de-emphasis filter combination has a peak gain of 10 for
2. The ceramic filters can be 30 kHz SFG455A3s made by Murata which have 30 kHz IF
3. Set your RF generator at 45.000 MHz, use a 1 kHz modulation frequency and a 6 kHz
4. The measured typical sensitivity for 12 dB SINAD should be 0.45 PV or 114 dBm at
5. The layout is very critical in the performance of the receiver. We highly recommend
6. The smallest RSSI voltage (i.e., when no RF input is present and the input is
7. All of the inductors, the quad tank, and their shield must be grounded. A 10 PF to
8. R5 can be used to bias the oscillator transistor at a higher current for operation above
Fig 4. Application circuit test setup
accurate measurements. Without the gain, the measurements may be affected by the
noise of the scope and HP339A analyzer. The de-emphasis filter has a fixed
6 dB/Octave slope between 300 Hz and 3 kHz.
bandwidth (they come in blue), or 16 kHz CFU455Ds, also made by Murata (they
come in black). All specifications and testing are done with the wideband filter.
deviation if you use 16 kHz filters, or 8 kHz if you use 30 kHz filters.
the RF input.
our demo board layout.
terminated) is a measure of the quality of the layout and design. If the lowest RSSI
voltage is 500 mV or higher, it means the receiver is in regenerative mode. In that
case, the receiver sensitivity will be worse than expected.
15 PF or higher value tantalum capacitor on the supply line is essential. A low
frequency ESR screening test on this capacitor will ensure consistent good sensitivity
in production. A 0.1 PF bypass capacitor on the supply pin, and grounded near the
44.545 MHz oscillator improves sensitivity by 2 dB to 3 dB.
45 MHz. Recommended value is 22 k:, but should not be below 10 k:.
RF GENERATOR
45 MHz
Rev. 01 — 1 November 2004
V
CC
1
through
(+3)
8
apply to
SCOPE
DC VOLTMETER
Figure
4:
Low-voltage mixer FM IF system
RSSI
HP339A DISTORTION
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
SA58640 DEMOBOARD
DE-EMPHASIS
C–MESSAGE
ANALYZER
AUDIO
FILTER
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SA58640
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