TA2012 datasheet(7/21 Pages) TOSHIBA

7 / 21 page

TA8132AN / AF , TA2012N / F

2002-10-30

Application Note

1. How to control the IF count output signal (pin(9) output)

TUN LED

OFF

Come out

Non output

· Whether or not there is the IF count output signal (pin(9) output) is determined by the and of the pin(8)

control voltage: V8 and tuning LED on / off switching.

In the condition of

V8: High (active high, VTH = 0.8V (typ.))

TUN LED: ON (Vin ≥ VL+2dBµV EMF (typ.))

the IF count output signal comes out from the pin(9).

In the case of the tuning LED function is not needed, it doesn't matter the pin(10) is opened.

· The output impedance of pin(9) is 1.5kΩ (typ.) (cf.P.4)

It is possible to reduce the IF count output signal level to add the resistance between the pin(9) and the VCC

line.

· The signal waveform is the rectangular wave, and the level is 500mVp-p (typ.)

2. How to control the divider of FM IF

Switch

VCC: 10.7MHz output

GND or OPEN: 1.3375MHz output (1 / 8 dividing)

3. How to adjust the IF count output sensitivity

· The IF count output sensitivity (search sensitivity)

Can be adjusted by varying the IF AMP gain for FM and varying the MIXER gain for AM.

This setting is made by changing the value of external resistance R2 which is connected to

pin(2).

· However, this is only possible at the auto-tuning mode. (external voltage supplied to pin(8) is at high level.)

The original again returns while receiving a broadcast station (supplied voltage to pin(8) is at low level.)

TA2012 Datasheet(PDF) 7 Page - Toshiba Semiconductor