3

Multimedia ICs

BA7655A / BA7655AF

Not designed for radiation resistance.

Parameter

Symbol

Min.

Typ.

Max.

Unit

Voltage

Conditions

Supply current

One channel

ICC1

—

4.6

7.0

mA

3.0

Set control voltage to 1V or less,

when only one channel is used.

Both channels

ICC2

—

7.8

12.0

Maximum output voltage

VMax.

2.5

2.8

—

5.0

Frequency characteristics

Gf

– 1.0

0.0

dB

3.0

Minimum voltage gain

GVMin. – 8.0

– 6.0

– 4.0

dB

2.0

f = 1MHz

Maximum voltage gain

GVMax.

4.0

6.0

8.0

dB

5.0

f = 1MHz

Secondary harmonic distortion

2HD

—

– 40

—

dB

3.0

Audio distortion

AD

—

1.0

—

%

3.0

Muting output voltage

VMUTE

—

—

100

mV

1.0

Set control voltage to 1 V or less

V S / N

—

– 60

—

dB

3.0

A S / N

—

– 60

—

dB

3.0

Audio

S / N

∗

Video

S / N

∗

1.0

f = 1kHz, THD = 1%

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

POWER SAVE MODE

8

6

4

2

0

–2

–4

–6

–8

–10

–12

–14

Control voltage (V)

Fig. 1 Voltage gain vs.

control voltage characteristics

The gain of a VCA (voltage-controlled amplifier) can be

varied by an external control voltage. By varying the

control voltage from 2V to 5V (in the case of a 5V

power supply), the gain of the amplifiers in this IC can

be varied over the range -6dB to +6dB (see Figs. 1

and 2 below).

When only one of the two amplifiers is being used, by

setting the voltage on the CTL pin of the unused ampli-

fier to 1V or less, it can be put into Power Save Mode.

In Power Save Mode, the circuit current for the IC is

cut by 40%, and the output is muted.

VCA

IN

OUT

Control voltage

Fig. 2

CTL Voltage

Status

2V ~ 5V

Variable gain

1V or less

Power save