TA2149BFNG TOSHIBA Semiconductor CORPORATION, TA2149BFNG Datasheet - Page 8

• Manufacturer Part Number: TA2149BFNG
• Description: 3 V Am/fm 1 Chip Tuner Ic For Digital Tuning System
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Application Note
1. AM Low-Cut Circuit
2. FM Detection Circuit
3. FM/AM switch and forced monaural switch.
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For the FM detection circuit, detection coil is able to use instead of ceramic discriminator.
Recommended circuit and recommended coil are as follows. (In this case, please take care that V
falls a little.)
FM/AM switch (pin 13)
Stereo/forced monaural switch (pin 14)
The AM Low-Cut action is carried out by the bypass of the high frequency
component of the positive-feedback signal at the AF AMP stage.
The external capacitor: C
The cut-off frequency fL is determined by the internal resistance
22 kΩ (Typ.) and the external capacitor C
In the case of the AM Low-Cut function is not needed, set up the value of C
In the condition of C
It is possible to reduce the recovered output level at AM mode, by additional resistance between the pin 3
and GND line.
FM/AM switchover and stereo/forced monaural switchover are done by pin 13 and pin 14.
V13: Low (Active Low, V
V13: OPEN
V14: Low (Active Low, V
V14: OPEN
Frequency
10.7 MHz
Test
f
L
=
2
×
π
×
(pF)
22
Co
51
1
×
V
10
CC
10
3
3
×
> = 1 µ F, the frequency characteristic has flat response at the low frequency.
C
V
th
th
Qo
45
CC
3
3
= 0.2 V (Typ.), I
= 0.2 V (Typ.), I
by-pass this component.
(Hz)
V
CE (sat)
14
1-2
⎯
2-3
⎯
Pin 10
3
V
Turns
th
th
as following;
CC
30 µ A (Typ.) → AM
30 µ A (Typ.) → Forced Monaural
1-3
30
8
V
CE (sat)
3
2
1
13
4-6
⎯
→ FM
→ Stereo
4
6
0.08UEW
(mmφ)
Wire
600BEAS-10018Z
Toko Co., Ltd.
3
Reference
TA2149BNG/BFNG
over 1 µF.
22 kΩ
22 kΩ
3
R
C
2006-04-11
3
in
(lim.)