BA7787FS datasheet(9/24 Pages) ROHM

9 / 24 page

Multimedia ICs

BA7786FP-Y / BA7787FS

•Circuit operation

(1) Gain between LINE IN L / LINE IN R and HP OUT L /

HP OUT R

GHP, the gain when EVR is at its maximum (VE = HP

VCC), is calculated as follows:

(2) Output level between SYSTEM BEEP IN and HP

OUT L / HP OUT R

Inputting a pulse wave to SYSTEM BEEP IN causes HP

OUT L and HP OUT R to output a pulse wave. The out-

put level of this pulse wave depends on the resistance

between pin 7 and GND. The level when EVR is at its

maximum (VE = HP VCC) is calculated as follows.

(4) Gain between PM BEEP IN and SP OUT 1 / SP OUT 2

This is calculated as follows.

(BA7786FP-Y only, BA7787FS: pin 8)

This path is output regardless of whether LIN MIX ON /

OFF is at the high or low level.

(3) Gain between SP IN L / SP IN R and SP OUT L / SP

OUT R (BA7786FP-Y)

This is calculated as follows.

This path is not controlled by EVR or the mute function.

(5) Gain between LINE IN L and LCH OUT

(BA7786FP-Y)

This gain (GHL) is calculated as follows.

Set so that 12k

56k. This gain attenuates accord-

ing to the pin 1 DC voltage (VE) (see Fig. 8). Mixing

input can be accommodated by attaching multiple resis-

tors.

Gain between SP IN and SP OUT 1 / SP OUT 2

(BA7787FS)

This is calculated as follows.

Set so that R

100k (VHB

1.1V). As with the path be-

tween LINE IN L / LINE IN R and HP OUT L / HP OUT

R, this level attenuates according to the pin 1 DC volt-

age.

(BA7786FP-Y only, BA7787FS: pin 15)

GHP

∗ LOG

(dB)

60k

1k + R

GSP

∗ LOG

(dB)

32k

1k + R

GSP

∗ LOG

(dB)

32k

1k + R

GSB

∗ LOG

(dB)

20k

1k + R

GHL

∗ LOG

(dB)

∗ R2

VHB

0.5

∗

∗ 60k (VP-P)

VCC – 0.7

13k + R

BA7787FS Datasheet(PDF) 9 Page - Rohm

BA7787FS Datasheet(HTML) 9 Page - Rohm

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Datasheet Download

Link URL