U4065B Datasheet, PDF (8/34 Pages) TEMIC Semiconductors – FM Receiver

AGCOUT
IMMIXOUT
AGCWB
Figure 10. Output of the Automatic Gain Control
10
1k
1V
ESD
The AGC output is an open collector output. The current of the pin diode is this current
multiplied by the current gain of the external PNP transistor. The DC voltage at the pin
may vary from 2 V to V_S, therefore, this pin can easily be used as an indicator of the
AGC regulation state.
Figure 11. Output of the Intermodulation Mixer
V_S
300
1V
ESD
11
The parallel output resistance is 330 Ω which allows the use of standard ceramic BPF
without any further matching network. It must be ensured that the ground pin of the filter
is free of AC signals.
Figure 12. Threshold Adjustment of the Wideband AGC
V_REF
35k
8 U4065B
32k
ESD
13
The threshold of the wideband AGC can be adjusted by an external resistor to ground.
The setting range is 10 dB. For minimum blocking, this pin is connected to ground. To
set the threshold to lower levels, the resistance should have a value of up to a few hun-
dred kΩ.
4807A–AUDR–05/04