Service manual

■IU01 (BA7790LS)
1. FUNCTION
(1) Circuit essential for a standard sound signal processing system as a PB AMP, REC AMP, ALC circuit, EQ selecting
switch and high voltage head switch have been intergrated onto a single 1 chip.
(2) Built-in LINE/TUNER INPUT selecting switch.
(3) Built-in summary 3 mode EQ switch and it can be obtained EQ carateristics of each mode.
(4) PB AMP is low noise and high performance.
(5) Built-in ALC circuit with variable ALC level for setting.
(6) No shock noise or ALC attack noise is generated when power source is turned ON or the mode is changed by means
of a ALC loop outside mute system.
2. Absolute Maximum Ratings (Ta = 25°C)
※ Derate 4.0mW/°C for the operating above Ta = 25°C
3. Recommended Operational Conditions (Ta = 25°C)
55
PIN MODE STOP REC PLAY REW/FWD REV/FF PAUSE STILL
10000000
2 4.6 4.6 4.6 4.6 4.6 4.6 4.6
30000000
40000000
5 11.2 11.2 11.2 11.2 11.2 11.2 11.2
6 4.7 4.7 4.7 4.7 4.7 4.7 4.7
7 11.4 11.4 11.4 11.4 11.4 11.4 11.4
8 4.7 4.7 4.7 4.7 4.7 4.7 4.7
9 0 0 3.8 0 3.7 0 0
10 4.7 4.7 4.7 4.7 4.7 4.7 4.7
11 0.6 0.6 5.2 0.6 5.2 0.6 5.2
12 5.3 5.3 5.3 5.3 5.3 5.3 5.3
13 4.6 4.6 4.6 4.6 4.6 4.6 4.6
14 0.6 0.6 0 0.5 0 0.5 0
15 5.4 5.4 5.3 5.4 5.3 5.4 5.4
16 5.3 5.3 5.3 5.3 5.3 5.3 5.3
17 0 0 0 0 5 0 5
18 5.3 5.3 5.3 5.3 5.3 5.3 5.3
19 5.4 5.4 5.3 5.3 5.4 5.4 5.4
20 0 0 0 0 0 0 0
21 5.4 5.4 5.3 5.4 5.4 5.4 5.4
22 5.4 5.4 5.3 5.4 5.4 5.3 5.3
23 0 0 0 1 0 0 0
24 0.5 5.2 0.5 0.5 0 0.5 0.5
Parameter Symbol Limits Unit
Supply voltage Vcc 13 V
Power dissipation Pd ※ 400 mW
Operating temperature Topr -10~+65 °C
Storage temperature Tstg -55~+125 °C
Parameter Symbol Range Unit
Power supply voltage Vcc 7.5~12.5 V
AUDIO IC BA7790LS
4. Pin Opertion