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

BD5423AEFS

●Electrical characteristic curves (Reference data) – Continued

(3) Under Stereo Operation(R

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

30

RL=4Ω
fin=1kHz

25

20

15

10

5

OUTPUT POWER (W)

0

8 1012141618

Fig. 23 Output power - Power supply voltage

100

90
80
70
60
50
40
30

EFFICIENCY (%)

20
10

0

0 5 10 15 20

OUTPUT POWER (W/ch)

Fig. 24 Efficiency - Output power Fig. 25 Efficiency - Output power

100

90
80
70
60
50
40
30

EFFICIENCY (%)

20
10

0

0 5 10 15 20

OUTPUT POWER (W/ch)

Fig. 26 Efficiency - Output power Fig. 27 Current consumption - Output power

L=4Ω)

THD=10%

VCC (V)

Vcc=10V

L

R

=4Ω

fin=1kHz

Vcc=16.5V

L

=4Ω

R
fin=1kHz

100

90
80
70
60
50
40
30

EFFICIENCY (%)

20
10

0

0 5 10 15 20

OUTPUT POWER (W/ch)

4

3

Vcc=10V

2

ICC (A)

1

0

0 5 10 15 20 25 30 35 40

TOTAL OUTPUT POWER (W)

Technical Note

Vcc=12V

L

=4Ω

R
fin=1kHz

Vcc=12V

Vcc=16.5V

RL=4Ω
fin=1kHz

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7/17

2010.05 - Rev.B

BD5423AEFS

5

●Pin Assignment

Technical Note

Top View

VCCA

BSP2P

VCCP2P

IN2

44

FIL A

GNDA

43

FIL P

39

40

41

42

VCCP2P

OUT2P

OUT2P

GNDP2

34

35

36

37

38

OUT2N

GNDP2

32

33

VCCP2N

VCCP2N

BSP2N

VHOLD

OUT2N

30

31

28

29

TM

ROSC

27

25

26

MS

24

OSC

23

FIL P

FIL A

GND A

2

1

IN1

PL M T1

VCCA

PW M 2

PW M 1

Limit

Pow er

3

4

5

PL M T3

PL M T2

PL M T4

●Outer Dimensions and Inscriptions

44

BD5423AEFS

0.85

1

1PIN MARK

1.0 MAX

0.8

Fig. 29 Outer Dimensions and Inscriptions of HTSSOP-A44 Package

DRIVER

2P

DRIVER

1P

7

8

6

BSP1P

VCCP1P

9

OUT 1P

VCCP1P

Fig. 28 Pin Assignment Diagram

18.

±

(MAX 18.85 include BURR)

0.1

(6.0)

Ramp

Clock

Control

Generator

Sof t Mute

Pow er- of f

Detector

DRIVER

2N

Under Vol tage Protection

DRIVER

1N

10

11

12

13

14

15

16

OUT 1P

GNDP1

GNDP1

OUT 1N

OUT 1N

VCCP1N

VCCP1N

Protections & Logi c

ERROR

WARNING

17

18

19

BSP1N

ERROR

WARNING

Ou tpu t Shor t Protecti on

High TemperatureProtection

Mute

Output DC Vol tage Protection

Control

N.C.

N.C.

20

21

22

N.C.

N.C.

MUTEX

TYPE

23

(5.0)

22

Lot No.

(Unit: mm)

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8/17

2010.05 - Rev.B

BD5423AEFS

●Explanation of Pin Functions (Provided pin voltages are typical values.)

No. Symbol Pin voltage Pin description Internal equalizing circuit

ch1 Analog signal input pin

1

44

2 PLMT1 3.5V

IN1
IN2

3.5V

ch2 Analog signal input pin

Input audio signal via a capacitor.

Voltage-to-current conversion pin for
output power limiter function

Connect a register.

Technical Note

3 PLMT2 -

4 PLMT3 -

5 PLMT4 3.5V

Current-to-voltage conversion pin for
output power limiter function

Connect a register.

Current-to-voltage conversion pin for
output power limiter function

Connect a register.

Bias pin for output power limiter function

Connect a register and a capacitor.

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9/17

2010.05 - Rev.B

BD5423AEFS

●Explanation of Pin Functions (continued)

No. Symbol Pin voltage Pin description Internal equalizing circuit

Technical Note

6 BSP1P -

7, 8 VCCP1P Vcc ch1 positive power system power supply pin

9, 10 OUT1P Vcc～0V

11, 12 GNDP1 0V ch1 power system GND pin

13, 14 OUT1N Vcc～0V

15, 16 VCCP1N Vcc ch1 negative power system power supply pin

17 BSP1N -

ch1 positive bootstrap pin
Connect a capacitor.

ch1 positive PWM signal output pin
Connect with output LPF.

ch1 negative PWM signal output pin
Connect with output LPF.

ch1 negative bootstrap pin
Connect a capacitor.

18 WARNING

19 ERROR

H: 5V

L: 0V

H: 5V

L: 0V

Warning output pin

Pin to notify operation warning.
H: Under warning
L: Normal operation

Connect a resister.

Error output pin

A pin for notifying operation errors.
H: Error
L: Normal operation

Connect a resister.

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10/17

2010.05 - Rev.B

BD5423AEFS

●Explanation of Pin Functions (continued)

No. Symbol Pin voltage Pin description Internal equalizing circuit

Audio mute control pin

20 MUTEX -

H: Mute off
L: Mute on

Technical Note

21, 22 N.C. -

23 OSC -

24 MS -

N.C. pin
Nothing is connected with IC internal circuit.

Sampling clock signal input/output pin

When using two or more sampling clocks,
connect via a capacitor.

Master/Slave switching pin

Switching of master/slave functions on a
sampling clock signal.
H: Slave operation
L: Master operation

25 ROSC 5.6V

26 TM 0～5V

Internal PWM sampling clock
frequency setting pin
Usually the pin is used open.
To adjust an internal sampling clock
frequency, connect a resister.

Audio muting constant setting pin

Connect a capacitor.

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11/17

2010.05 - Rev.B

BD5423AEFS

●Explanation of Pin Functions (continued)

No. Symbol Pin voltage Pin description Internal equalizing circuit

Instantaneous power interruption
detecting voltage setting pin

27 VHOLD 0.68×Vcc

Connect a capacitor.
To adjust a detecting voltage, connect a
resister.

Technical Note

28 BSP2N -

29, 30 VCCP2N Vcc ch2 negative power system power supply pin

31, 32 OUT2N Vcc～0V

33, 34 GNDP2 0V ch2 power system GND pin

35, 36

37, 38 VCCP2P Vcc ch2 positive power system power supply pin

OUT2P Vcc～0V

ch2 negative bootstrap pin
Connect a capacitor.

ch2 negative PWM signal output pin
Connect an output LPF.

ch2 positive PWM signal output pin
Connect an output LPF.

39 BSP2P -

40 VCCA Vcc Analog system power pin

41 FILP

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Vcc+35

12

ch2 positive bootstrap pin
Connect a capacitor.

PWM system bias pin
Connect a capacitor.

12/17

2010.05 - Rev.B

BD5423AEFS

●Explanation of Pin Functions (continued)

No. Symbol Pin voltage Pin description Internal equalizing circuit

Analog signal system bias pin

42 FILA 3.5V

Connect a capacitor.

Technical Note

43 GNDA 0V Analog system power supply pin

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13/17

2010.05 - Rev.B

BD5423AEFS

●Application Circuit Diagram.

・Vcc=10V～16.5V

Technical Note

C35 C31

ch-2

INPUT

GNDA V CCA

C44

2.2µ F

43

44

GNDA

C43

10µ F

C41

1µ F

C42

10µ F

42

FIL A

C40

0.1µ F

41

FIL P

VCCP

C39

0.68µ F

38

39

40

VCCA

0.22µ F 0.22µ F

L35

15µ H

C38

10µ F

C37 C29

0.1µ F 0.1µ F

35

36

37

DRIVER

2P

Ω

4

SP ch2

C32
1µ F

SL AV E

MASTER

L31

15µ H

GNDD

GND P

C28

0.68µ F

C27

3.3µ F

0.1µ F

C26

OPEN

28

30

31

32

33

34

DRIVER

2N

29

27

Pow er- of f

Detector

25

26

Ramp

Generator

Sof t M ut e

CLK I/O

C23

0.1µ F

24

23

Clock

Control

PW M 2

PW M 1

Under Vol tage Protecti on

DRIVER

1P

Pow er

Limit

2

3

4

R3

Ω

0.1µ F

22k

5

R4

Ω

C5

GNDA

1

Ω

R2

22k

22k

GNDA

C1

2.2µF

ch-1

INPUT

6

C6

0.68µ F

VCCP

7

8

9

10

C7

0.1µ F

C8

10µ F

L9

15µ H

C9

0.22µ F

11

12

C13

0.22µ F

C10

1µ F

DRIVER

1N

13

GNDP

14

C15

0.1µ F

L13

15µ H

15

16

C17

0.68µ F

Protecti ons & L ogic

ERROR

WARNING

17

18

19

R18

100kΩ100k

ERROR OUTPUT

WARNING OUTPUT

Output Short Protection

H ig h T emper atur e Pr ot ec ti on

Ω

R19

Output DC Vol tage Protection

Mute

Control

N.C.

N.C.

20

21

22

N.C.

N.C.

MUTE

Fig. 30 Circuit diagram under stereo operation with 4- load

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SP ch1

14/17

Ω

4

2010.05 - Rev.B

BD5423AEFS

Technical Note

Table 1 BOM list for stereo operation with 4- load

No. Item Part Number Vendor

1 IC BD5423AEFS ROHM HTSSOP-A44 - - - - 1 IC1

2 C GRM219B31E684KA88D MURATA 2012 0805 0.68µF 25V ±10% ±10% 4 C6, C17, C28, C39

3 C GRM188R11H104KA93 MURATA 1608 0603 0.1µF 50V ±10% ±10% 5 C7, C15, C29, C37, C40

4 C GRM31MB11H224KA01 MURATA 3216 1206 0.22µF 50V ±10% ±10% 4 C9, C13, C31, C35

5 C 25ST225M3216 Rubycon 3225 1210 2.2µF 25V ±20% ±5% 2 C1, C44

6 C 50ST105M3225 Rubycon 3225 1210 1µF 50V ±20% ±5% 2 C10, C32

7 C GRM21BB31E335KA75 MURATA 2012 0805 3.3µF 25V ±10% ±10% 1 C27

8 C GRM188B11E104KA MURATA 1608 0603 0.1µF 25V ±10% ±10% 3 C5, C23, C26

9 C GRM21BB11C105KA MURATA 2012 0805 1µF 16V ±10% ±10% 1 C41

10 C GRM21BB31C106KE15 MURATA 2012 0805 10µF 16V ±10% ±10% 1 C42

11 C 25SVPD10M SANYO 6666 2626 10µF 25V ±20% ±25% 3 C8, C38, C43

12 R MCR01MZPF2202 ROHM 1005 0402 22k 50V ±1% ±200ppm/℃ 3 R2, R3, R4

13 R MCR01MZPF1003 ROHM 1005 0402 100k 50V ±1% ±200ppm/℃ 2 R18, R19

No. Item Part Number Vendor

14 L 7G09B-150M SAGAMI 10×9×10 15µH×2 ±20% 44mmax. 4.1A max. 2 L9, L13, L31, L35

Configuration

mm inch

Configuration

mm

Val ue

Value Tolerance

Rated

voltage

Tolerance

Resistance

DC

Temperature

characteristics

Rated

DC Current

Quantity Reference

Quantity Reference

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© 2010 ROHM Co., Ltd. All rights reserved.

15/17

2010.05 - Rev.B

BD5423AEFS

Technical Note

●Notes for use

1. About absolute maximum ratings
If an applied voltage or an operating temperature exceeds an absolute maximum rating, it may cause destruction of a
device. A result of destruction, whether it is short mode or open mode, is not predictable. Therefore, provide a physical
safety measure such as fuse, against a special mode that may violate conditions of absolute maximum ratings.

2. About power supply line
As return of current regenerated by back EMF of output coil happens, take steps such as putting capacitor between
power supply and GND as a electric pathway for the regenerated current. Be sure that there is no problem with each
property such as emptied capacity at lower temperature regarding electrolytic capacitor to decide capacity value. If the
connected power supply does not have sufficient current absorption capacity, regenerative current will cause the voltage
on the power supply line to rise, which combined with the product and its peripheral circuitry may exceed the absolute
maximum ratings. It is recommended to implement a physical safety measure such as the insertion of a voltage clamp
diode between the power supply and GND pins.

3. Potential of GND (11, 12, 33, 34, and 43 pins)
Potential of the GND terminal must be the lowest under any operating conditions.

4. About thermal design
Perform thermal design with sufficient margins, in consideration of maximum power dissipation Pd under actual operating
conditions. This product has an exposed frame on the back of the package, and it is assumed that the frame is used with
measures to improve efficiency of heat dissipation. In addition to front surface of board, provide a heat dissipation pattern
as widely as possible on the back also.
A class-D power amplifier has heat dissipation efficiency far higher than that of conventional analog power amplifier and
generates less heat. However, extra attention must be paid in thermal design so that a power dissipation Pdiss should not
exceed the maximum power dissipation Pd.

Maximum power dissipation

Power dissipation

jmax

Pd





aj



1



PP Odiss












W






W 1-





Tjmax: Maximum temperature junction = 150[℃]
Ta: Operating ambient temperature [℃]
θja: Package thermal resistance [℃/W]
Po: Output power [W]
η: Efficiency

Ta-T

5. About operations in strong electric field
Note that the device may malfunction in a strong electric field.

6. Thermal shutdown (TSD) circuit
This product is provided with a built-in thermal shutdown circuit. When the thermal shutdown circuit operates, the output
transistors are placed under open status. The thermal shutdown circuit is primarily intended to shut down the IC avoiding
thermal runaway under abnormal conditions with a chip temperature exceeding Tjmax = 150℃, and is not intended to
protect and secure an electrical appliance. Accordingly, do not use this circuit function to protect a customer's electrical
appliance.

7. About shorting between pins and installation failure
Be careful about direction and displacement of an LSI when installing it onto the board. Faulty installation may destroy
the LSI when the device is energized. In addition, a foreign matter getting in between LSI pins, pins and power supply,
and pins and GND may cause shorting and destruction of the LSI.

8. About power supply startup and shutdown
When starting up a power supply, be sure to place the MUTEX pin (pin 20) at “L” level. When shutting down a power
supply also, be sure to place the pin at “L” level. Those processes reduce pop noises generated upon turning on and off
the power supply. In addition, all power supply pins must be started up and shut down at the same time.

9. About WARNING output pin (pin 18) and ERROR output pin (pin 19)
A WARNING flag is output from the WARNING output pin upon operation of the high-temperature protection function and
under-voltage protection function. And an ERROR flag is output from the ERROR output pin upon operation of VCC/GND
shorting protection function and speaker DC voltage applying protection function. These flags are the function which the
condition of this product is shown in. The use which aimed at the protection except for this product is prohibition.

10. About N.C. pins (pins 21 and 22)
The N.C. (Non connection) pins are not connected with an internal circuit. Leave the pins open or connect them to GND.

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© 2010 ROHM Co., Ltd. All rights reserved.

16/17

2010.05 - Rev.B

BD5423AEFS

●Ordering part number

Technical Note

B D

Part No.

HTSSOP-A44

44 23

9.5±0.2

7.5±0.1

1

0.85

1.0MAX

0.85±0.05

0.08±0.05

5 4 2 3 A E F S

Part No.

18.5±0.1

(MAX 18.85 include BURR)

(6.0)

1PIN MARK

0.8

0.37

+0.05

-

0.04

22

0.08

0.08

(5.0)

S

4°

S

M

+

6°

−

4°

0.5±0.15

1.0±0.2

+0.05

0.17

-

0.03

(Unit : mm)

Package
EFS:HTSSOP-44

<Tape and Reel information>

Embossed carrier tape (with dry pack)Tape

Quantity

Direction
of feed

1500pcs
E2

The direction is the 1pin of product is at the upper left when you hold

()

reel on the left hand and you pull out the tape on the right hand

Reel

-E 2

Packaging and forming specification
E2: Embossed tape and reel

1pin

Order quantity needs to be multiple of the minimum quantity.

∗

Direction of feed

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© 2010 ROHM Co., Ltd. All rights reserved.

17/17

2010.05 - Rev.B

Notes

No copying or reproduction of this document, in part or in whole, is permitted without the
consent of ROHM Co.,Ltd.

The content specied herein is subject to change for improvement without notice.

The content specied herein is for the purpose of introducing ROHM's products (hereinafter
"Products"). If you wish to use any such Product, please be sure to refer to the specications,
which can be obtained from ROHM upon request.

Examples of application circuits, circuit constants and any other information contained herein
illustrate the standard usage and operations of the Products. The peripheral conditions must
be taken into account when designing circuits for mass production.

Great care was taken in ensuring the accuracy of the information specied in this document.
However, should you incur any damage arising from any inaccuracy or misprint of such
information, ROHM shall bear no responsibility for such damage.

The technical information specied herein is intended only to show the typical functions of and
examples of application circuits for the Products. ROHM does not grant you, explicitly or
implicitly, any license to use or exercise intellectual property or other rights held by ROHM and
other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the
use of such technical information.

Notice

The Products specied in this document are intended to be used with general-use electronic
equipment or devices (such as audio visual equipment, ofce-automation equipment, commu­nication devices, electronic appliances and amusement devices).

The Products specied in this document are not designed to be radiation tolerant.

While ROHM always makes effor ts to enhance the quality and reliability of its Products, a
Product may fail or malfunction for a variety of reasons.

Please be sure to implement in your equipment using the Products safety measures to guard
against the possibility of physical injury, re or any other damage caused in the event of the
failure of any Product, such as derating, redundancy, re control and fail-safe designs. ROHM
shall bear no responsibility whatsoever for your use of any Product outside of the prescribed
scope or not in accordance with the instruction manual.

The Products are not designed or manufactured to be used with any equipment, device or
system which requires an extremely high level of reliability the failure or malfunction of which
may result in a direct threat to human life or create a risk of human injury (such as a medical
instrument, transportation equipment, aerospace machinery, nuclear-reactor controller, fuel­controller or other safety device). ROHM shall bear no responsibility in any way for use of any
of the Products for the above special purposes. If a Product is intended to be used for any
such special purpose, please contact a ROHM sales representative before purchasing.

If you intend to export or ship overseas any Product or technology specied herein that may
be controlled under the Foreign Exchange and the Foreign Trade Law, you will be required to
obtain a license or permit under the Law.

Thank you for your accessing to ROHM product informations.
More detail product informations and catalogs are available, please contact us.

ROHM Customer Support System

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http://www.rohm.com/contact/

R1010

A