SA58641 Datasheet, PDF (13/17 Pages) NXP Semiconductors – High performance mixer FM IF system with high-speed RSSI

Philips Semiconductors
High performance mixer FM IF system
with high-speed RSSI
Objective data
SA58641
Table 1. DECT Application Circuit Electrical Characteristics
RF frequency = 110.592 MHz; IF frequency = 9.8 MHz; RF level = –45 dBm; FM modulation = 100 kHz with ±288 kHz peak deviation.
SYMBOL
PARAMETER
TEST CONDITIONS
TYPICAL UNITS
Mixer/Osc section (ext LO = 160 mV_RMS)
PG
Conversion power gain
13
dB
NF
Noise Figure at 110 MHz
12
dB
IIP3
Third order input intercept
Matched f1 = 110.592 MHz; f2 = 110.892 MHz
–15
dBm
R_IN
C_IN
IF section
RF input resistance
RF input capacitance
690
Ω
3.6
pF
IF amp gain
330 Ω load
38
dB
Limiter amp gain
330 Ω load
54
dB
Data level
3 dB data bandwidth
R_LOAD = 3 kΩ
130
mV_RMS
700
kHz
RF/IF section (internal LO)
System RSSI output
RF level = –10 dBm
1.4
V
System S/N¹
RF level = –83 dBm
10
dB
NOTE:
1. 10 dB S/N corresponds to BER = 10^–3.
RF GENERATOR
110.592 MHz
LO / GENERATOR
120.392 MHz
SA58641 DEMO BOARD
RSSI DATA
V_CC = 5 V
DC VOLTMETER
SCOPE
SPECTRUM
ANALYZER
SR02527
Figure 11. SA58641 Application Circuit Test Set Up
NOTES:
1. RF generator: Set your RF generator at 110.592 MHz, use a 100 kHz modulation frequency and a ±288 kHz deviation.
2. Layout: The layout is very critical in the performance of the receiver. We highly recommend our demo board layout.
3. 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 500 mV or higher, it means the receiver is in regenerative mode. In that case, the receiver sensitivity
will be worse than expected.
4. Supply bypass and shielding: All of the inductors, the quad tank, and their shield must be grounded. A 0.1 µF bypass capacitor on the supply
pin improves sensitivity.
2004 Dec 16
13