ta2149bfn TOSHIBA Semiconductor CORPORATION, ta2149bfn Datasheet - Page 8

• Manufacturer Part Number: ta2149bfn
• 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 kW (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
´
p
´
22
(pF)
Co
51
1
´
V
10
CC
3
10
3
´
> = 1 mF, the frequency characteristic has flat response at the low frequency.
C
V
th
th
Qo
45
3
CC
3
by-pass this component.
(Hz)
= 0.2 V (Typ.), I
= 0.2 V (Typ.), I
V
CE (sat)
14
1-2
¾
2-3
¾
Pin 10
3
V
Turns
th
th
CC
as following;
30 mA (Typ.) ® AM
30 mA (Typ.)® Forced Monaural
1-3
30
8
V
CE (sat)
3
2
1
13
4-6
¾
® FM
® Stereo
4
6
0.08UEW
(mmf)
Wire
600BEAS-10018Z
Toko Co., Ltd.
3
Reference
over 1 mF.
TA2149BN/BFN
22 kW
22 kW
3
R
C
2001-12-21
3
in
(lim.)