10

Video ICs

BA7795LS / BA7795FS

(1) ALC level

Set the ALC level in the range – 8dBV to 0dBV by

selecting the values of resistors R1 and R2 connected

between BIAS, ALC LEVEL and GND.

The formula for approximating the value of this resistor

is as follows:

If the ALC level setting is too low, level variation will

– 6dBV), and conversely, if the level is too high, the

level variation will decrease, but distortion will

increase.There is almost no temperature characteristic,

as shown in the formula above. Use care when setting

it.

(2) Mute signal

Apply the mute signal shown below at power on and

off. If the muting time is short, a pop sound will be audi-

ble, particularly when the power is switched on.

Also, be certain to apply the mute signal when switch-

ing between PB / LINE / TU. In the case of LINE / TU

switching, it is possible to suppress switching noise by

applying a time constant to the signal, in which case it

is not necessary to apply the mute signal.

(3) Recording control

Do not switch the PB and REC modes on togther. This

will cause faulty operation.

(4) Line output

The line output can drive a load resistance of up to

2k

Ω. Depending on the type of load, it can cause local

oscillation (eg. large capacitive loads that draw large

current), so caution is required. In particular, when

there is a possibility that the line output will be connect-

ed to a shielded cable, or line cable, connect a resistor

of about 1k

Ω in series with the output so that the

capacitive load is not directly coupled to the IC output

terminal.

2sec or more

(H)

MUTE CTRL

LINE OUT

(H)

Fig. 7

2

=

•

•

1

2

1

2

•

2

BIAS

ALC LEVEL

Fig. 6