Sharp MD-M3 Service Manual page 69

IC3 VHiLA6548//-1: Focus/Tracking/Spin/Sled Driver (LA6548)
Pin No. Terminal Name
1 VCC Power supply. (pin24 and short)
2 MUTE ON/OFF for all CH output.
3* VIN1 Channel 1 input terminal.
4 VG1 Channel 1 input terminal. (gain control)
5 VO1+ Channel 1 output terminal. (non-inverted)
6 VO1– Channel 1 output terminal. (inverted)
7 VO2– Channel 2 output terminal. (inverted)
8 VO2+ Channel 2 output terminal. (non-inverted)
9 VG2 Channel 2 input terminal. (gain control)
10* VIN2 Channel 2 input terminal.
11 REG-OUT Connect the external PNP transistor collector here. 3.3 VREG output.
12 REG-IN Connect the external PNP transistor base here.
13* RESET Reset output.
14* CD Reset output delay time setting. (externally installed capacitor)
15* VIN3 Channel 3 input terminal.
16 VG3 Channel 3 input terminal. (gain control)
17 VO3+ Channel 3 output terminal. (non-inverted)
18 VO3– Channel 3 output terminal. (inverted)
19 VO4– Channel 4 output terminal. (inverted)
20 VO4+ Channel 4 output terminal. (non-inverted)
21 VG4 Channel 4 input terminal. (gain control)
22* VIN4 Channel 4 input terminal.
23 VREF Apply the reference voltage.
24 VCC Power supply. (pin1 and short)
In this unit, the terminal with asterisk mark (*) is (open) terminal which is not connected to the outside.
Set the ground (minimum potential) at the center frame.
AMP
1
MUTE
MUTE
2
(Output ON/OFF)
11k
3
Focus
Input
4
5
Focus
Level
Output
shift
6
7
Tracking
Level
Output
shift
8
9
Tracking
15.4k
Input
11k
10
11
AMP 3.3V
AMP 3.3V
12
Vcc
Figure 69 BLOCK DIAGRAM OF IC
Function
24
23
15.4k
15.4k
11k
22
21
20
Level
shift
19
18
Level
shift
17
16
15.4k
11k
15
14
RESET 13
– 69 –
MD-M3/D1
VREF
Input
Spindle
Input
Spindle
M
Output
Sled
M
Output
Sled
Input