SA2111C Datasheet, PDF (4/9 Pages) Silan Microelectronics Joint-stock – 3V AM/FM +MPX TUNER IC(FOR MECHANICAL TUNING)

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Pin No.
8
9
10
11
12
13
14
Symbol
FM IF IN
GND
TUN LED
ST LED
QUAD
R-OUT
L-OUT
15
LPF1
16
LPF2
17
MPX IN
18
DET OUT
19
AFC
20
AM OSC
21
FM OSC
22
RF VCC
23
FM RF OUT
24
AM RF IN
FUNCTION DESCRIPTION
Application note:
1. AM low-cut circuit
Description
FM IF INPUT
GND for AM, FM IF, FM MPX stage
tuning LED
Stereo LED
FM QUAD. Detector
R-channel Output
L-channel Output
• LPF terminal for synchronous detector
• VCO stop terminal V15=VCC→VCO STOP
• LPF terminal for phase detector
• Bias terminal for AM/FM SW circuit
V16=VCC→AM
V16=OPEN→FM
MPX INPUT
FM & AM DETECT OUTPUT
AUTO FREQUENCY CONTROL
AM OSC
FM OSC
VCC for FM OSC stage
FM RF OUTPUT
AM RF INPUT
SA2111C
When pin3 is open, no AF signal can pass through the AMP stage because of the common mode.
When the value of C3 that connected to pin3 is over 1uF, all AF signal can pass through the AMP stage.
The cut-off frequency fL is determined by the internal resistance 22kΩ (Typ.) and the external capacitor C3 as
below:
1
fL =
3 ^(Hz)
2 x ʌ x 22 x 10 x C3
It is possible to reduce the recovered output level at AM mode, by additional resistance between the pin (3)
and GND line.
HANGZHOU SILAN MICROELECTRONICS CO.,LTD
Http: www.silan.com.cn
Rev: 1.1 2005.10.26
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