SA5209 Datasheet, PDF (7/17 Pages) NXP Semiconductors – Wideband variable gain amplifier

Philips Semiconductors
Wideband variable gain amplifier
Product specification
SA5209
1997 Nov 07
50Ω
SOURCE
2:1 TURNS RATIO
LC TUNED
TRANSFORMER
+5V
5209
50Ω
V_AGC
+1V
Figure 6. Narrowband Noise Optimization
50Ω
SOURCE
+5V
MINI CIRCUITS
4:1 BALUN OR
EQUIVALENT
5209
1:4
50Ω
V_AGC
+1V
Figure 7. Broadband Gain Optimization
50Ω
SOURCE
4:1 TURNS RATIO
LC TUNED
TRANSFORMER
+5V
5209
50Ω
V_AGC
+1V
Figure 8. Narrowband Gain Optimization
50Ω
SOURCE
50Ω
+5V
5209
50Ω
V_AGC
+1V
Figure 9. Simple Amplifier Configuration
50Ω
SOURCE
+5V
5209
50Ω
V_AGC
+1V
Figure 10. Unterminated Configuration
50Ω
OUTPUT
This circuit will exhibit about a 7dB
noise figure with approximately
22dB gain. Narrowband circuits
have the advantage of greater stabil-
ity, particularly when multiple de-
vices are cascaded.
SR00242
50Ω
OUTPUT
This circuit will exhibit about an 8dB
noise figure with 24dB gain.
SR00243
50Ω
OUTPUT
This circuit will exhibit approximate-
ly an 8dB noise figure and 25dB gain.
SR00244
50Ω
OUTPUT
The noise figure of this configuration
will be approximately 15dB.
SR00245
50Ω
OUTPUT
With the 50Ω source left untermi-
nated, the noise figure is 9dB.
SR00246
7