ROHM BH3544F, BH3541F Datasheet

BH3541F / BH3544F

Optical disc ICs

Headphone amplifier for CD-ROMs

BH3541F / BH3544F

The BH3541F and BH3544F are digital-source dual headphone amplifiers. The BH3541F has a fixed gain of 0dB and
the BH3544F has a fixed gain of 6dB so that external gain setting is unnecessary. Both the BH3541F and BH3544F have
internal mute functions so that prevention of the popping sound when power is turned on and off is greatly simplified.
Also, these ICs are equipped with thermal shutdown circuits to prevent damage from short circuits.

Product name

BH3541F

!!!!

BH3544F

Applications

Devices that use the headphone output from CD-ROMs, CDs, MDs, personal computers, notebook computers,
camcorders, etc.

Fixed gain

0dB
6dB

Features

!!!!

1) Internal mute function to prevent popping sounds when the power is turned on and off.

2) Built-in thermal shutdown circuit (150°C) to prevent damage to the IC if a short circuit occurs.

3) Compact SOP8 pin package.

Absolute maximum ratings

!!!!

Parameter Symbol Limits Unit

Applied voltage V
Power dissipation Pd 450 mW
Operating temperature Topr
Storage temperature Tstg

∗Reduced by 4.5mW for each increase in Ta of 1°C over 25°C.

Recommended operating conditions

!!!!

Parameter

Power supply voltage

(Ta = 25°C)

Max

7.0 V

∗

−25 ~ +75

−55 ~ +125 °C

(Ta = 25°C)

Symbol Min. Typ. Max. Unit

CC

V

2.8

−

6.5 V

°C

Optical disc ICs

Block diagram

!!!!

V

TSD

BH3541F / BH3544F

CC

OUT2 BIAS IN2

BIAS

0dB

(6dB)

+

+

0dB

(6dB)

MUTE

5678

180k
(90k)

180k
(90k)

OUT1

21

MUTE IN1 GND

3 4

( ) The values in parenthesis are for the BH3544F.

Optical disc ICs

Pin descriptions

!!!!

BH3541F / BH3544F

Pin No. Pin name Internal equivalent circuit

1

OUT1

Pin voltage

I / O

O 2.1V

V

CC

1

7

2

OUT2

MUTE

O 2.1V

(V

CC=

0.1V

I

5V)

7

10k

V

CC

2

(When open)

190k

V

CC

3

IN1

I 2.1V

Function

Output pin

Mute control pin

(set to low for prevention of
popping noise when power
is turned on and off).

Operating : High
Muting : Low (open)

Input pin

3

5

IN2

I 2.1V

CC

=5V)

(V

5

2.1V

6

4

8I

BIAS

GND

CC

V

I / O

I −

(V

CC

=5V)

6

−

180k

BIAS

V

CC

Bias pin
(the external 47µF
capacitor also serves as the
anti-pop time constant,
therefore make the proper

60k

BIAS

60k

considerations be changing
it).