BA6780 / BA6780FP-Y

Optical disc ICs

Block diagram and pin descriptions

BA6780

18

17

16

15

14

13

12

11

10

1

2

3

4

5

6

7

8

9

REVERSIBLE DRIVER

FWD/REV CONTROLLER

Vref

Vconst

17.1k

20k

40k

40k

DRIVE BUFFER

V / I

Vref

3.2k

10k

10k

Vref

10k

Vref

Vref

Vref

10k

10k

10k

10k

10k

10k

DETECTOR

10k

10k

DRIVE BUFFER

GOVERNOR DRIVER

FWD/REV CONTROLLER

THERMAL

SHUT DOWN

1/2

FIN2

RIN2

C

τ2

FBIN

−

FBIN

+

OUT2

+

OUT2

−

OUT1

−

OUT1

+

Vreg

Vref

Iout

RIN1

FIN1

Pin No.

Pin name

I/O

Function

I

Input pin for setting high output voltage for the reversible driver

2

FIN1

I

Input pin for forward control signal for the reversible driver

3

RIN1

Input pin for reverse control signal for the reversible driver

4

Iout

O

Governor load current detector output (open collector

)

5

Vref

O

Internal reference voltage pin

6

Vreg

O

4.6V constant voltage output

I

I

Power supply (

+)

8

OUT1

+

Reversible driver output (

+)

9

OUT1

−

O

Reversible driver output (

−)

10

OUT2

−

O

Governor output (

−)

11

OUT2

+

O

Governor output (

+)

O

12

FBIN

+

I

Governor load current detector amplifier input (

+)

13

FBIN

−

Governor load current detector amplifier input (

−)

14

I

Power supply (

−) (connection within substrate)

15

C

τ 2

I

For connection of capacitor for the governor PWM filter

16

RIN2

I

Governor reverse control signal input

I

17

FIN2

I

Governor forward control signal input

18

Input pin for setting high output voltage for the governor

I

∗1