TA2149BFNG TOSHIBA Semiconductor CORPORATION, TA2149BFNG Datasheet - Page 9

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

4. V
5. How to control the Divider of FM OSC.
6. How to adjust the IF Count Output Sensitivity
This ICs have two voltage supply terminals, V
stage). Set up the potential difference between V
case that this IC doesn’t operate normally.
Divider of FM OSC ON/OFF switching is controlled by external pull-up resistor of pin 19.
In case of Divider of FM OSC is used, it is necessary to set up the value of R under 470 Ω (typ.).
When R is over 470 Ω , it is feared that Divider is not operating. (At this time, buffer output frequency is
equal to FM OSC frequency.)
Which ever Divider of FM OSC is used or not, AM OSC buffer frequency and output level is same.
IF count output sensitivity can be adjusted by changing the value of external resistance at pin 17.
This ICs have IF signal level detector in pin 9. When DC voltage of pin 9 is high than threshold, IF count
output signal come out from the pin 17.
And this threshold is controlled by value of external resistance at pin 19.
CC
Line
Mode
FM
AM
OSC
OSC
AM
FM
OPEN
OPNE
SW8
ON
ON
buff
buff
65
60
55
50
45
40
35
30
0
V CC = 3 V
f = 10.7 MHz
∆f = 75 MHz
1/16
Output Frequency
1/1
or
0.5
1/16 FM OSC
External resistance of pin-17 (kΩ)
1/1 FM OSC
1/1 FM OSC
1
1.5
CC
CC
9
(for AM, FM IF, MPX stage) and RF V
IF sens (FM)
V IF (FM)
19
2
and RF V
2.5
Output Level (Typ.)
R
SW8
RF V
110 mVrms
35 mVrms
75 mVrms
CC
3
CC
0.4 V (typ.) or less, otherwise there is the
3.5
buff out
350
300
250
200
150
100
50
0
TA2149BNG/BFNG
CC
(for FM RF
2006-04-11