mc13145fta Lansdale Semiconductor, Inc., mc13145fta Datasheet - Page 10

• Manufacturer Part Number: mc13145fta
• Description: Uhf Wideband Receiver Subsystem Lna, Mixer, Vco, Prescaler, If Subsystem, Coiless Detector
• Manufacturer: Lansdale Semiconductor, Inc.

ML13145
Page 10 of 17
45, 46
Pin
43
44
7
Symbol/Type
Lim Dec1,
Lim Dec2
Lim In
RSSI
V CC
See Figure 5.
Lim Dec1
Lim Dec2
IF Dec1
IF Dec2
Lim In
IF Out
RSSI
Figure 5. Limiter Amplifier Functional Diagram
IF In
45
44
46
39
38
40
41
7
Figure 4. IF Amplifier Functional Diagram
Description
www.lansdale.com
V CC , Positive Supply Voltage
Limiting Amplifier Input
Limiting amplifier input source impedance is 330 Ω.
This amplifier has 84 dB of gain with 3.0 dB
bandwidth of 40 MHz; this enables the IF and
limiting ampliers chain to hard limit on noise.
If Decoupling
These pins are decoupled to V CC to provide stable
operation of the 2nd IF limiting amplifier.
RSSI
The RSSI circuitry in the 2nd, 3rd, & 4th amplifier
stages outputs a current when the output of the
previous stage enters limiting. The net result is a
RSSI current which represents the logarithm of the
IF input voltage. An external resistor to ground is
used to provide a voltage output.
Σ
Σ
RSSI
Description
LANSDALE Semiconductor, Inc.
Lim+
Lim–
Demod
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