SDIP24-P-300-1.78 查看數據表（PDF） - Toshiba

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产品描述 (功能)

生产厂家

SDIP24-P-300-1.78

3V AM/FM 1 Chip Tuner IC (for Digital Tuning System)

Toshiba 

TA2149BN/BFN

4. VCC Line

This ICs have two voltage supply terminals, VCC (for AM, FM IF, MPX stage) and RF VCC (for FM RF

stage). Set up the potential difference between VCC and RF VCC 0.4 V (typ.) or less, otherwise there is the

case that this IC doesn’t operate normally.

5. How to control the Divider of FM OSC.

AM

OSC

buff

FM

OSC

buff

1/1

or

1/16

RF VCC

R

SW8

19

buff out

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 W (typ.).

When R is over 470 W, 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.

Mode

FM

AM

SW8

OPEN

ON

OPNE

ON

Output Frequency

1/1 FM OSC

1/16 FM OSC

1/1 FM OSC

Output Level (Typ.)

35 mVrms

110 mVrms

75 mVrms

6. How to adjust the IF Count Output Sensitivity

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.

65

350

60

VIF (FM)

300

55

250

50

200

IF sens (FM)

45

150

40

VCC = 3 V

35 f = 10.7 MHz

Df = 75 MHz

30

0

0.5

1

1.5

2

2.5

3

External resistance of pin-17 (k9)

100

50

0

3.5

9

2001-12-21

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