SA2111C

HANGZHOU SILAN MICROELECTRONICS CO.,LTD

Rev: 1.1

2005.10.26

Http: www.silan.com.cn

Page 4 of 10

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Pin No.

Symbol

Description

8

FM IF IN

FM IF INPUT

9

GND

GND for AM, FM IF, FM MPX stage

10

TUN LED

tuning LED

11

ST LED

Stereo LED

12

QUAD

FM QUAD. Detector

13

14

R-OUT

L-OUT

R-channel Output

L-channel Output

15

LPF1

• LPF terminal for synchronous detector

• VCO stop terminal V15=VCC→VCO STOP

16

LPF2

• LPF terminal for phase detector

• Bias terminal for AM/FM SW circuit

V16=VCC

→AM

V16=OPEN

→FM

17

MPX IN

MPX INPUT

18

DET OUT

FM & AM DETECT OUTPUT

19

AFC

AUTO FREQUENCY CONTROL

20

AM OSC

AM OSC

21

FM OSC

FM OSC

22

VCC for FM OSC stage

23

FM RF OUT

FM RF OUTPUT

24

AM RF IN

AM RF INPUT

FUNCTION DESCRIPTION

Application note:

1. AM low-cut circuit

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 22k

Ω (Typ.) and the external capacitor C3 as

below:

C3

x

3

10

x

22

x

x

2

1

=

(Hz)

It is possible to reduce the recovered output level at AM mode, by additional resistance between the pin (3)

and GND line.