Service manual

– 69 –
MD-M3/D1
IC3 VHiLA6548//-1: Focus/Tracking/Spin/Sled Driver (LA6548)
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)
Pin No.
Function
Terminal Name
Set the ground (minimum potential) at the center frame.
Level
shift
Level
shift
11k
11k
15.4k
15.4k
1 24
AMP
2 23
MUTE
3 22
Focus
Output
Tracking
Output
Tracking
Input
Focus
Input
Spindle
Output
Sled
Output
Sled
Input
Spindle
Input
VREF
Input
4 21
5 20
M
M
6 19
7 18
8 17
9 16
10 15
11 14
AMP 3.3V
12 13
Vcc
Level
shift
AMP 3.3V
RESET
Level
shift
MUTE
(Output ON/OFF)
11k
11k
15.4k
15.4k
Figure 69 BLOCK DIAGRAM OF IC
In this unit, the terminal with asterisk mark (*) is (open) terminal which is not connected to the outside.