SA637 Ver la hoja de datos (PDF) - Philips Electronics
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SA637 Datasheet PDF : 11 Pages
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Philips Semiconductors RF Communications Products
Low-voltage digital IF receiver
Product specification
SA637
RF GENERATOR
83.16MHz
SA637 DEMO BOARD
RSSI
LIMITER
OUTPUT
VCC = 3V
DC VOLTMETER
SPECTRUM
ANALYZER
Figure 3. SA637 Application Circuit Test Set Up
NOTES:
1. Carrier-to-Noise (C/N): Connect a spectrum analyzer to Pin 10 or 11; set your RF generator to 83.16MHz or 455kHz above your LO fre-
quency, modulation off; set the spectrum analyzer resolution bandwidth to 300Hz; and adjust your RF input level until the C/N = 26dB. Use
video averaging. Assure that LIMOUT(+) and LIMOUT(–) are matched symetrically.
2. Ceramic filters: The ceramic filter can be SFGCC455BX-TC made by Murata which has 30kHz IF bandwidth.
3. Sensitivity: The measured typical sensitivity for 12dB SINAD should be 0.45µV or -114dBm at the RF input.
4. Layout: The layout is very critical in the performance of the receiver. We highly recommend our demo board layout.
5. RSSI: The smallest RSSI voltage (i.e., 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 500mV or higher, it means the receiver is in regenerative mode. In that case, the receiver sensitivity
will be worse than expected.
6. Supply bypass and shielding: All of the inductors, the quad tank, and their shield must be grounded. A 0.1µF bypass capacitor on the sup-
ply pin improves sensitivity.
October 27, 1993
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