mc13150ftb Lansdale Semiconductor, Inc., mc13150ftb Datasheet - Page 6

• Manufacturer Part Number: mc13150ftb
• Description: Narrowband Fm Coilless Detector If Subsystem
• Manufacturer: Lansdale Semiconductor, Inc.

ML13150
IF AMPLIFIER
The first IF amplifier section is composed of three differential
stages. This section has internal dc feedback and external
input decoupling for improved symmetry and stability. The
total gain of the IF amplifier block is approximately 42 dB at
455 kHz. Figure 8 shows the gain of the IF amplifier as a
function of the IF frequency.
The fixed internal input impedance is 1.5 kΩ; it is designed
for applications where a 455 kHz ceramic filter is used and
no external output matching is necessary since the filter
requires a 1.5 kΩ source and load impedance.
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800
750
700
650
600
50
45
40
35
30
25
20
0.01
0
V in = 100 µV
R in = 50 Ω
R out = 1.4 kΩ
BW (3.0 dB) = 2.4 MHz
T A = 25°C
20
Figure 8. IF Amplifier Gain
Figure 10. F adj Voltage
versus IF Frequency
versus F adj Current
0.1
f, FREQUENCY (MHz)
F adj CURRENT (µA)
40
60
1.0
V CC = 3.0 Vdc
T A = 25°C
80
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100
10
Overall RSSI linearity is dependent on having total midband
attenuation of 10 dB (4.0 insertion loss plus 6.0 dB
impedance matching loss) for the filter. The output of the IF
amplifier is buffered and the impedance if 1.5kΩ.
LIMITER
The limiter section is similar to the IF amplifier section
except that six stages are used. The fixed internal input
impedance is 1.5 kΩ. The total gain of the limiting
amplifier sections is approximately 96 dB. This IF limiting
amplifier section internally drives the quadrature detector
section.
120
100
3.5
3.0
2.5
2.0
1.5
1.0
0.5
80
60
40
20
0
0
400
0
V CC = 3.0 Vdc
Slope at 455 kHz = 9.26 kHz/µA
200
420
Figure 11. BW adj Current
Figure 9. F adj Current
versus IF Frequency
versus IF Frequency
f, IF FREQUENCY (kHz)
f, IF FREQUENCY (kHz)
V CC = 3.0 Vdc
BW
400
440
LANSDALE Semiconductor, Inc.
26 kHz/µA
460
600
800
480
1000
500
Issue A