17

Multimedia ICs

BA7786FP-Y / BA7787FS

No.

Use

Standard value

R1

Used to set the gain from LINE IN L / LINE IN R (pins 2 and 4) to HP OUT

L / HP OUT R (pins 24 and 23)

27k

Ω

R2

(See section 1, on circuit operation for the formula.)

27k

Ω

R3

A wide range of mixing ratios can be set by changing the values of

27k

Ω

R4

R1, R2 and R3 (or R4, R5 and R6).

27k

Ω

R5

27k

Ω

R6

27k

Ω

R7

33k

Ω

R8

33k

Ω

R9

33k

Ω

R10

Used to set the output level from SYSTEM BEEP IN (pin 6) to HP OUT

L / HP OUT R (pins 24 and 23). (See section 2, on circuit operation for the formula.)

390k

Ω

R11

• No need to attach. Connect pin 8 to a ground.

—

R13

• Used to set the gain from PM BEEN IN (pin 9) to SP OUT L / SP OUT R

(pins 10, 11, 16 and 17). (See section 4, on circuit operation for the formula.)

18k

Ω

R14

R15

• The load resistor for HP OUT R.

100

Ω

• The load resistor for HP OUT L.

100

Ω

Used to set the gain from SP IN L / R (pins 21 and 20) to SP OUT L / R (pins 10, 11,

16 and 17). (See section 3, on circuit operation for the formula.)

15k

Ω

R17

R16

15k

Ω

C1

• The coupling capacitor for LINE IN L

0.1

µF

C2

• The coupling capacitor for LINE IN R

0.1

µF

C3

• The ripple rejection capacitor for the bias pin

47

µF

C4

• The coupling capacitor for SYSTEM BEEP IN

0.1

µF

C5

• No need to attach

—

C6

• The coupling capacitor for PM BEEP IN

0.1

µF

C7

100

µF

C8

0.1

µF

C9

• The coupling capacitor for HP OUT R

47

µF

C10

• The coupling capacitor for HP OUT L

47

µF

C11

100

µF

C12

0.1

µF

C13

• The coupling capacitor for SP IN R

0.1

µF

C14

• The coupling capacitor for SP IN L

0.1

µF

VR1

• Used to change the pin 1 DC voltage

20k

Ω

BA7786FP-Y

Resistors for mixing SYSTEM BEEP IN (pin 6). Because the threshold voltage

between the high and low levels is fixed inside the IC, these resistors should be

set to 33k

Ω