Aiwa AD F990 Service Manual

Page: 1 / 40
left right
Aiwa AD F990 Service Manual

Extracted text from Aiwa AD F990 Service Manual (Ocr-read)


Page 15

Pin No.

Pin mark

Function

OSC1

This pin supplies external operation
clock. Inputs the mechanism control
400 Hz.

®

0562

Internal clock oscillating pin attached
to the external resonance circit. Not
connected.

CI»

Compu~brain data output CAL a):
Set ta Hi when 2" bit is set.

C1

Compu-brain data output CAL '1:
Set to Hi when 2‘ bit is set.

C2

Oompu-brain data output CAL 2:
Set to Hi when 2’ bit is set.

C3

Compu-brain data output CAL 3:
Set to Hi when 23 bit is set.

Compu brain data output CAL 4:
Set to Hi when 2‘ bit is set.

®®®®®®

El?

Comm-brain data output E0 $2
Set to Hi when 2° bit is set.

E1

Compu-brain data output E01:
Set to Hi when 2‘ bit is set.

EZ

Compu-brain data output E0 2:
Set to Hi when 2“ bit is set.

E3

Compubram data output E0 3:
Set to Hi when 23 bit is set:

E4

Compu-brain data output E0 4:
Set to Hi when 2‘ on is set.

®®®®®

MEG ¢v

Set to Hi when 30.31.32, 83, B4 of
the data are set to wow dUring bias
adjustment.

To change recording equalizer.

MEQI

Set to Hi when BO, 51.32.53.321 of
the data are set to 1111‘! during bias
adjustment.

To change recording equalizer.

HOLD

HOLD mode demand input Din.

INT

Interruption demand input pin. Not
connected.

VDD

Power pin. Connected to the backup
capacitor circuit. Approx. 5.3V in
general. Approx. 5.6V just after
power OFF,and then gradually drops
in several hours.

K

Compuhrain key. CompuAbrain start/
reset when this is set to L0.

K-CST

For cassette detection. Set to Hi
when a cassette is present.

15

Page 22

3-1-2. Pin function |C5V

This is the attenuation quantity UP/DOWN control oscillator,
and the UP/DOWN speed is determined by its time constant.

Pin No. Mark Function Remarks
2 ROUY, 10 sttep attenuator outputs L, R Symmetry
15 LOUT, signal applied to IN is attenuated in 7 steps, 0 — Gods in
10 dB steps.
ouTl Q
3 R-IN, 10 dB-step attenuator inputs
14 L‘IN, INx
4 A-GND GND pins A-GND
13 ‘—
INI
5 R-INz 2 dB-step attenuator inputs
12 L-IN, 0m-2 O
6 R-OUT2 2 dB-step attenuator outputs
11 L-OU'I', Signal applied to IN is attenuated in 5 steps, 0 — 8 dB in
2 dB steps.
7 INH INHIBIT pin
When this pin is set to "L", all input/output are shut offsetting
the INHIBIT mode.
(STATE HOLDINGI Normal operation in "H" level.
8 D00 Attenuation quantity indicator DC ourrent output,
Attenuation quantity 0 ~— on is classified into 13 steps and
current of approx. 50 uA/step is output.
50 wt 0 dB
R
550 uA
" Attenuation quantity can be made
symmetrical to the DC voltage by
w inserting a resistor between this
pin and GND.
. . . VDD
9 05¢ Oscillator CR. connection pin

22