Optical disc ICs
zBlock diagram and pin descriptions
BA6780
BA6780 / BA6780FP-Y
VIN2
FIN2
RIN2
Cτ2
18
17
16
15
VIN
1/2
GOVERNOR DRIVER
FWD/REV CONTROLLER
THERMAL
SHUT DOWN
VEE
FBIN−
FBIN+
OUT2+
OUT2−
14
13
12
11
10
VEE
10k
10k
DETECTOR
10k
DRIVE BUFFER
10k
10k
10k
10k
Vref
3.2k
10k
10k 10k
10k
Vref
Vref
Vref
Vref
V/I
VIN
1
VIN1
VEE
REVERSIBLE DRIVER
FWD/REV CONTROLLER
IOUT
2
3
4
FIN1
RIN1
Iout
40k 40k
20k
VCC
VEE
Vref
5
17.1k VEEVCC
Vconst
6
7
Vref
Vreg
VCC
DRIVE BUFFER
8
OUT1+
9
OUT1−
Pin No.
Pin name
1
VIN1
2
FIN1
3
RIN1
4
Iout
5
Vref
6
Vreg
7
VCC
8
OUT1+
9
OUT1−
10
OUT2−
11
OUT2+
12
FBIN+
13
FBIN−
14
VEE
15
Cτ 2
16
RIN2
17
FIN2
18
VIN2
∗1 Refer to operating notes.
I/O
Function
I
Input pin for setting high output voltage for the reversible driver
I
Input pin for forward control signal for the reversible driver
I
Input pin for reverse control signal for the reversible driver
O
Governor load current detector output (open collector∗1 )
O
Internal reference voltage pin
O
4.6V constant voltage output
I
Power supply (+)
O
Reversible driver output (+)
O
Reversible driver output (−)
O
Governor output (−)
O
Governor output (+)
I
Governor load current detector amplifier input (+)
I
Governor load current detector amplifier input (−)
I
Power supply (−) (connection within substrate)
I
For connection of capacitor for the governor PWM filter
I
Governor reverse control signal input
I
Governor forward control signal input
I
Input pin for setting high output voltage for the governor