ROHM BD5423AEFS Technical data

Middle Power Class-D Speaker Amplifiers

Analog Input / BTL Output
Class-D Speaker Amplifier

BD5423AEFS

●Description

BD5423AEFS is a 17W + 17W stereo class-D power amplifier IC, developed for space-saving and low heat-generation
applications such as low-profile TV sets. The IC employs state-of-the-art Bipolar, CMOS, and DMOS (BCD) process
technology that eliminates turn-on resistance in the output power stage and internal loss due to line resistances up to an
ultimate level. With this technology, the IC has achieved high efficiency of 90% (10W + 10W output with 8 load), which is
the top class in the industry. The IC, in addition, employs a compact back-surface heat radiation type power package to
achieve low power consumption and low heat generation and eliminates necessity of installing an external radiator, up to a
total output of 34W. This product satisfies both needs for drastic downsizing, low-profile structures and powerful, high­quality playback of the sound system.

●Features

1) A high efficiency of 90% (10W + 10W output with 8 load),
which is the highest grade in the industry and low heat-generation.

2) An output of 17W + 17W (12V, with 4 load) is allowed without an external heat radiator.

3) Driving a lowest rating load of 4 is allowed.

4) Pop noise upon turning power on/off and power interruption has been reduced.

5) High-quality audio muting is implemented by soft-switching technology.

6) An output power limiter function limits excessive output to speakers.

7) High-reliability design provided with built-in protection circuits against high temperatures,
against VCC shorting and GND shorting, against reduced-voltage, and against applying DC voltage to speaker.

8) A master/slave function allowing synchronization of multiple devices reduces beat noises.

9) Adjustment of internal PWM sampling clock frequencies (250kHz to 400kHz)
allows easy protective measures against unwanted radio emission to AM radio band.

10) A compact back-surface heat radiation type power package is employed.
HTSSOP-A44 (5mm × 7.5mm × 1.0mm, pitch 0.8mm )

●Absolute Maximum Ratings

A circuit must be designed and evaluated not to exceed absolute maximum rating in any cases and even momentarily, to
prevent reduction in functional performances and thermal destruction of a semiconductor product and secure useful life and
reliability.

The following values assume Ta =25℃. For latest values, refer to delivery specifications.

Parameter Symbol Ratings

Supply voltage VCC +20 V

Power dissipation Pd

Input voltage for signal pin VIN -0.2 ～ +7.2 V Pin 1, 44 (Note 1)

Unit Conditions

Pin 7, 8, 15, 16, 29, 30, 37, 38, 40
(Note 1, 2)

2.0 W (Note 3)

4.5 W (Note 4)

No.10075EBT02

Input voltage for control pin VCONT -0.2 ～ Vcc+0.2 V Pin 20, 24 (Note 1)

Input voltage for clock pin VOSC -0.2 ～ +7.2 V Pin 23 (Note 1)

Operating temperature range Topr -40 ～ +85 ℃

Storage temperature range Tstg -55 ～ +150 ℃

Maximum junction temperature Tjmax +150 ℃

(Note 1) A voltage that can be applied with reference to GND (pins 11, 12, 33, 34, and 43)
(Note 2) Pd and Tjmax=150℃ must not be exceeded.
(Note 3) 70mm × 70mm × 1.6mm FR4 One-sided glass epoxy board (Back copper foil 0%) installed.
If used under Ta=25℃ or higher, reduce 16mW for increase of every 1℃. The board is provided with thermal via.
(Note 4) 70mm × 70mm × 1.6mm FR4 Both-sided glass epoxy board (Back copper foil 100%) installed.
If used under Ta=25℃ or higher, reduce 36mW for increase of every 1℃. The board is provided with thermal via.

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1/17

2010.05 - Rev.B

BD5423AEFS

●Operating Conditions

The following values assume Ta =25℃. Check for latest values in delivery specifications.

Parameter Symbol Ratings Unit Conditions

Technical Note

Supply voltage VCC

Load resistance RL 4 ～ 16  (Note 5)

(Note 5) Pd should not be exceeded.

●Electrical Characteristics

Except otherwise specified T
For latest values, refer to delivery specifications.

Parameter Symbol Limits

Whole circuit

Circuit current 1
(Sampling mode)

Circuit current 2
(Muting mode)

Control circuit

“H” level input voltage VIH 2.3～12 V SDX, MUTEX, MS

“L” level input voltage VIL 0～0.8 V SDX, MUTEX, MS

Audio circuit

Voltage gain GV 28 dB PO = 1W

a = 25℃, VCC = 12V, fIN = 1kHz, Rg = 0, RL = 8、MUTEX="H", MS="L"

ICC1 25 mA With no signal

ICC2 10 mA MUTEX = “L”

+10～+16.5

Unit Conditions

V Pin 7, 8, 15, 16, 29, 30, 37, 38, 40

Maximum output power 1 (Note 6) PO1 10 W THD+N = 10%, RL = 8

Maximum output power 2 (Note 6) PO2 17 W THD+N = 10%, RL = 4

Total harmonic distortion (Note 6) THD 0.1 % PO = 1W, BW=20Hz～20kHz

Crosstalk CT 85 dB PO = 1W, Rg = 0, BW = IHF-A

Output noise voltage
(Sampling mode)

Residual noise voltage
(Muting mode)

Internal sampling clock frequency FOSC 250 kHz MS = “L” (In master operation)

(Note 6) The rated values of items above indicate average performances of the device, which largely depend on circuit layouts, components,
and power supplies. The reference values are those applicable to the device and components directly installed on a board specified by us.

VNO 80 µVrms Rg = 0, BW = IHF-A

VNOM 1 µVrms Rg = 0, BW = IHF-A, MUTEX = “L”

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2/17

2010.05 - Rev.B

BD5423AEFS

●Electrical characteristic curves (Reference data)

(1) Under Stereo Operation(R

L=8)

100

10

Vcc=12V

=8Ω

R

L

BW=20～20kHz

1

THD+N (%)

6kHz

0.1

0.01

0.001 0.01 0.1 1 10 100

1kHz

100Hz

OUTPUT POWER (W)

Fig. 1 THD+N － Output power Fig. 2 THD+N － Frequency

40

35

30

25

20

15

10

VOLTAGE GAIN (dB)

Vcc=12V

L

=8Ω

R
Po=1W
L=33µH
C=0.47µF
Cｇ=0.1µF

5

0

10 100 1000 10000 100000

FREQUENCY (Hz)

Fig. 3 Voltage gain - Frequency Fig. 4 Crosstalk - Frequency

-20

-40

0

Vcc=12V

L

=8Ω

R
fin=1kHz
BW=20～20kHz

-60

CROSSTALK (dB)

-80

-100

0.001 0.01 0.1 1 10 100
OUTPUT POWER (W)

Fig. 5 Crosstalk - Output power Fig. 6 Output power - Power supply voltage

Technical Note

100

Vcc=12V

=8Ω

R

L

10

1

THD+N (%)

0.1

0.01
10 100 1000 10000 100000

FREQUENCY (Hz)

0

-20

-40

-60

CROSSTALK (dB)

-80

-100
10 100 1000 10000 100000

FREQUENCY (Hz)

20

RL=8Ω
fin=1kHz

THD=10%

15

10

5

OUTPUT POWER (W)

0

8 1012 141618

VCC (V)

Po=1W
BW=20～20kHz

Vcc=12V

L

=8Ω

R
Po=1W
BW=20～20kHz

THD=1%

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3/17

2010.05 - Rev.B

BD5423AEFS

●Electrical characteristic curves (Reference data) – Continued

100

90
80
70
60
50
40
30

EFFICIENCY (%)

20
10

Vcc=10V

L

=8Ω

R
fin=1kHz

0

0 5 10 15 20

OUTPUT POWER (W/ch)

Fig. 7 Efficiency - Output power Fig. 8 Efficiency - Output power

100

90
80
70
60
50
40
30

EFFICIENCY (%)

20
10

Vcc=16.5V

L

R

=8Ω

fin=1kHz

0

0 5 10 15 20

OUTPUT POWER (W/ch)

Fig. 9 Efficiency - Output power Fig. 10 Current consumption - Output power

100

RL=8Ω

RL=8Ω

90

無信号時

80

Without signal

70
60
50
40

ICC (mA)

30
20
10

Sampling

Mute

0

8 1012141618

VCC (V)

Fig. 11 Current consumption - Power supply voltage Fig. 12 FFT of Output Noise Voltage

Technical Note

100

90
80
70
60
50
40
30

EFFICIENCY (%)

20
10

0

0 5 10 15 20

OUTPUT POWER (W/ch)

3

Vcc=12V

2

ICC (A)

1

0

0 5 10 15 20 25 30 35 40

0

-20

-40

-60

-80

-100

NOISE FFT (dBV)

-120

-140
10 100 1000 10000 100000

Vcc=10V

TOTAL OUTPUT POWER (W)

Vcc =12V

Vcc=12V

R

L

=8Ω

R

=8Ω

L

無信号時

Without signal

BW=20～20kHz

BW=20 ～ 20kHz

FREQUENCY (Hz)

Vcc=12V

L

R

=8Ω

fin=1kHz

Vcc=16.5V

RL=8Ω
fin=1kHz

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4/17

2010.05 - Rev.B

BD5423AEFS

●Electrical characteristic curves (Reference data) – Continued

Technical Note

MUTEX

Pin 20

TM

Pin 26

Speaker

Output

10V/div

5V/div

2V/div

10msec/div

Fig. 13 Wave form when Releasing Soft-mute Fig. 14 Wave form when Activating Soft-mute

VCCA

VHOLD

Pin 27

TM

Pin 26

Speaker

Output

20msec/div

5V/div

5V/div

2V/div

Fig. 15 Wave form on Instantaneous Power Interruption

(20msec / div)

Vcc=12V

=8

R

L

Ω

Po=500mW
fin=500Hz

Vcc=12V
R

=8

L

Ω

Po=500mW
fin=3kHz

M

UTEX

Pin 20

TM

P

in 26

Speaker

Output

VCCA

VHOLD

Pin 27

TM

Pin 26

Speaker

Output

10msec/div

5V/div

5V/div

2msec/div

10V/div

5V/div

2V/div

2V/div

Vcc=12V
R

=8

L

Po=500mW
fin=500Hz

Vcc=12V
R

=8

L

Po=500mW

fin=3kHz

Fig. 16 Wave form on Instantaneous Power Interruption

(2msec / div)

Ω

Ω

Soft Clip

Speaker

Output

Soft Clip

200μsec/div

5V/div

Fig. 17 Wave form on Output Power Limiter function

(Po = 5W)

Vcc=12V
R

=8

L

Ω

Po=5W
THD+n=10%
fin=1kHz
R2=91k

Ω

R3=22k

Ω

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5/17

2010.05 - Rev.B

BD5423AEFS

●Electrical characteristic curves (Reference data) – Continued

(2)Under Stereo Operation(R

25

RL=6Ω
fin=1kHz

20

15

10

5

OUTPUT POWER (W)

0

8 1012 141618

Fig. 18 Output power - Power supply voltage

100

90
80
70
60
50
40
30

EFFICIENCY (%)

20
10

0

0 5 10 15 20 25

Fig. 19 Efficiency - Output power Fig. 20 Efficiency - Output power

100

90
80
70
60
50
40
30

EFFICIENCY (%)

20
10

0

0 5 10 15 20 25

Fig. 21 Efficiency - Output power Fig. 22 Current consumption - Output power

Dotted lines of the graphs indicate continuous output power to be obtained on musical signal source or by installing
additional heat sinks.

L=6)

THD=10%

VCC (V)

OUTPUT POWER (W/ch)

OUTPUT POWER (W/ch)

Vcc=10V

L

=6Ω

R
fin=1kHz

Vcc=16.5V

L

R

=6Ω

fin=1kHz

100

90
80
70
60
50
40
30

EFFICIENCY (%)

20
10

0

0 5 10 15 20 25

OUTPUT POWER (W/ch)

4

3

Vcc=12V

Vcc=10V

2

ICC (A)

1

0

0 5 10 15 20 25 30 35 40 45 50

TOTAL OUTPUT POWER (W)

Technical Note

Vcc=12V

L

R

=6Ω

fin=1kHz

Vcc=16.5V

RL=6Ω
fin=1kHz

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6/17

2010.05 - Rev.B