Rohm BD5446EFV Technical Note

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Middle Power Class-D Speaker Amplifiers

Class-D Speaker Amplifier
for Digital Input

BD5446EFV

●Description

BD5446EFV is a Class D Speaker Amplifier designed for Flat-panel TVs in particular for space-saving and low-power
consumption, delivers an output power of 20W+20W. This 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 can achieve high efficiency of 87% (10W+10W output with 8Ω load). In
addition, the IC is packaged in a compact reverse heat radiation type power package to achieve low power consumption
and low heat generation and eliminates necessity of external heat-sink up to a total output power of 40W. This product
satisfies both needs for drastic downsizing, low-profile structures and many function, high quality playback of sound system.

●Features

1) BD5446EFV has two system of digital audio interface.
(I

2) Within the wide range of the power supply voltage, it is possible to operate in a single power supply. (10~26V)

3) It contributes to miniaturizing, making to the thin type, and the power saving of the system by high efficiency and low heat.

4) S/N of the system can be optimized by adjusting the gain setting among 8 steps. (20~34dB / 2dB step)

5) It has the output power limitation function that can be adjusted to an arbitrary output power.

6) The decrease in sound quality because of the change of the power supply voltage is prevented with the feedback

7) It provides with the best stereo DAC output for the headphone usage. As a result, the output of the selection of the

8) Eliminates pop noise generated when the power supply goes on/off, or when the power supply is suddenly shut off.

9) BD5446EFV is a highly reliable design to which it has various protection functions.
(High temperature protection, Under voltage protection, Output short protection, Output DC voltage protection and

●Applications

Flat Panel TVs (LCD, Plasma), Home Audio, Desktop PC, Amusement equipments, Electronic Music equipments, etc.,

2

S/LJ format, SDATA: 16 / 20 / 24bit, LRCLK: 32kHz / 44.1kHz / 48kHz, BCLK: 64fs (fixed), SYS_CLK: 256fs (fixed))

circuitry of the output. In addition, a low noise and low distortion are achieved.

digital input in two systems is possible.

High quality muting performance is realized by using the soft-muting technology.

Clock stop protection)

No.10075EBT14

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Technical Note

●Absolute maximum ratings (Ta=25℃)

Parameter

Symbol Ratings Unit Conditions

Supply voltage VCC 30 V Pin 25, 28, 29, 53, 54 *1 *2

2.0 W *3

Power dissipation Pd

4.5 W *4

6.2 W *5

Input voltage VIN -0.3 ~ 4.5 V Pin 7 ~ 18, 21 *1

Open-drain terminal voltage V

Operating temperature range T

Storage temperature range T

Maximum junction temperature T

*1 The voltage that can be applied reference to GND (Pin 6, 36, 37, 45, 46).
*2 Do not, however exceed Pd and Tjmax=150℃.
*3 70mm×70mm×1.6mm, FR4, 1-layer glass epoxy board (Copper on bottom layer 0%)

Derating in done at 16mW/℃ for operating above Ta＝25℃.
*4 70mm×70mm×1.6mm, FR4, 2-layer glass epoxy board (Copper on bottom layer 100%)
Derating in done at 36mW/℃ for operating above Ta＝25℃. There are thermal via on the board.
*5 70mm×70mm×1.6mm, FR4, 4-layer glass epoxy board (Copper on bottom layer 100%)
Derating in done at 49.6mW/℃ for operating above Ta＝25℃. There are thermal via on the board.

-0.3 ~ 30 V Pin24 *1

ERR

-25 ~ +85 ℃

opr

-55 ~ +150 ℃

stg

+150 ℃

jmax

●Operating conditions (Ta=25℃)

Parameter

Symbol Ratings Unit Conditions

Supply voltage VCC 10 ~ 26 V Pin 25, 28, 29, 53, 54 *1 *2

Minimum load impedance
(Speaker Output)

Minimum load impedance
(DAC Output)

*6 Do not, however exceed Pd.
* No radiation-proof design.

5.4 Ω *6

R

L_SP

R

20 kΩ Pin 22, 23

L_DA

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Technical Note

●Electrical characteristics

(Unless otherwise specified Ta=25℃,Vcc=13V,f=1kHz,RL_SP=8Ω,RL_DA=20kΩ,RESETX=3.3V,MUTEX=3.3V,PDX=3.3V,
Gain=20dB,fs=48kHz)

Item Symbol

Limits

Min Typ Max

Unit Conditions

Tota l ci r cu i t

Circuit current I

Circuit current
(Power down mode)
Open-drain terminal
Low level voltage

- 45 90 mA

CC1

- 1.5 3 mA

I

CC2

V

- - 0.8 V Pin 24,IO=0.5mA

ERR

Pin 25, 28, 29, 53, 54
No load
Pin 25, 28, 29, 53, 54,No load
RESETX=0V,MUTEX=0V,PDX=0V

Regulator output voltage 1 V

Regulator output voltage 2 V

5.0 5.5 6.0 V Pin 1, 27

REG_G

3.0 3.3 3.6 V Pin 5

REG_3

High level input voltage VIH 2.5 - 3.3 V Pin 7 ~ 18, 21

Low level input voltage VIL 0 - 0.8 V Pin 7 ~ 18, 21

Input current
(Input pull-down terminal)

33 66 132 µA Pin 7 ~ 18, 21,VIN = 3.3V

I

IH

Speaker Output

Maximum momentary
output power 1
Maximum momentary
output power 2

P

- 10 - W

O1

- 20 - W

P

O2

THD+n=10%
GAIN=26dB
VCC=18V, THD+n=10%
GAIN =26dB

*7

*7

Total harmonic distortion THDSP - 0.07 - % PO=1W, BW=20~20kHz *7

Crosstalk CTSP 65 80 - dB PO=1W, BW=IHF-A *7

Output noise voltage
(Sampling mode)
Residual noise voltage
(Mute mode)

PWM sampling frequency

V

- 140 280 µVrms -∞dBFS, BW=IHF-A *7

NO_SP

V

- 5 10 µVrms MUTEX=0V,-∞dBFS, BW=IHF-A *7

NOR_SP

f

- 512 - KHz fs=32kHz *7

PWM1

f

- 705.6 - KHz fs=44.1kHz *7

PWM2

f

- 768 - KHz fs=48kHz *7

PWM3

DAC Output

Maximum output voltage V

0.85 1.0 - Vrms 0dBFS,THD+n=1%

OMAX

Channel Balance CB -1 0 1 dB 0dBFS

Total harmonic distortion THDDA - 0.05 0.5 % -20dBFS,BW=20~20kHz

Crosstalk CTDA 65 80 - dB 0dBFS,BW=IHF-A

Output noise voltage V

Residual noise voltage V

*7 These items show the typical performance of device and depend on board layout, parts, and power supply.
The standard value is in mounting device and parts on surface of ROHM’s board directly.

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- 10 20 µVrms -∞dBFS, BW=IHF-A

NO_DA

- 3 10 µVrms

NOR_DA

MUTEX=0V,PDX=0V,

-∞dBFS, BW=IHF-A

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2010.05 - Rev.B

BD5446EFV

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r

g

t

t

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Technical Note

●Electrical characteristic curves(VCC=13V,Ta=25℃,RL_SP=8Ω,RL_DA=20kΩ,Gain=20dB,fin=1kHz,fs=48kHz)

Measured by ROHM designed 4 layer board.

100

90
80
70
60
50
40

ICC(mA)

30
20
10

Sampling

0

8 101214161820 222426 28

VCC(V)

Fig.1 Fig.2 Fig.3

Current consumption

- Power supply voltage

Mute

44
40
36
32
28
24
20
16
12

8

OUTPUT POWER(W/ch)

4
0

8 10 121416 18202224 2628

THD=10%

THD=1%

VCC(V)

Output power

- Power supply voltage

3

VCC=13V

2

ICC(A)

1

0

0 5 10 15 20 25 30 35 40

TOTAL OUTPUT POWER(W)

Current consumption

ut powe

- Out

100

90
80
70
60
50
40
30

EFFICIENCY(%)

20
10

0

024681012

OUTPUT POWER(W/ch)

Fig.4 Fig.5 Fig.6

Efficiency - Output power

30
28

Po=1W
L=22µH

26

C=0.47µF

24

C

=0.068µF

22
20
18
16
14

VOLTAGE G AIN( dB)

12
10

10 100 1k 10k 100k

FREQUENCY(Hz)

Voltage gain - Frequency

0

Without signal

-20

BW=20～20KHz

-40

-60

-80

-100

NOISE FFT(dBV)

-120

-140

10 100 1k 10k 100k

FREQUENCY(Hz)

FFT of Output noise voltage

100

BW=20～20KHz

10

1

THD+N(%)

0.1

0.01

0.001 0.01 0.1 1 10 100

6KHz

1KHz

100Hz

OUTPUT POWER(W)

Fig.7

THD+N - Output power

100

Po=1W
BW=20～20KHz

10

1

THD+N(%)

0.1

0.01

10 100 1k 10k 100k

FREQUENCY(Hz)

Fig.8

THD+N - Frequency

0

-10

BW=20～20KHz

-20

-30

-40

-50

-60

-70

CR OSSTALK(dB)

-80

-90

-100

0.001 0.01 0.1 1 10

OUTPUT POWER(W)

Fig.9

Crosstalk - Output power

0

-10

Po=1W
BW=20～20KHz

-20

-30

-40

-50

-60

-70

CR OSSTALK(dB)

-80

-90

-100

10 100 1k 10k 100k

FREQUENCY(Hz)

fin=300Hz
Po=3.3W

5V/div

2V/div

Speaker outpu

MUTEX

10ms/div

Speaker outpu

MUTEX

Fig.10 Fig.11 Fig.12

Crosstalk –Frequency

Wave form when

Releasing Soft-mute

Wave form when

Activating Soft-mute

VCC=18V

2V/div

10ms/div

fin=300Hz
Po=3.3W

5V/div

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BD5446EFV

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Technical Note

●Electrical characteristic curves(VCC=18V,Ta=25℃,R

Measured by ROHM designed 4layer board.

100

90
80
70
60
50
40
30

EFFICIENCY(%)

20
10

0

0 5 10 15 20

OUTPUT POWER(W/ch)

Fig.13 Fig.14 Fig.15

Efficiency – Output power

40
38
36
34
32
30
28
26

V OL TAGE G AI N(d B)

24
22
20

10 100 1k 10k 100k

Voltage gain - Frequency

100

BW=20～20KHz

10

1

THD+N(%)

0.1

0.01

0.001 0.01 0.1 1 10 100

6KHz

1KHz

100Hz

OUTPUT POWER(W)

Fig.16

THD+N - Output power

100

10

1

THD+N(%)

0.1

0.01

10 100 1k 10k 100k

0

Po=1W

-10

BW=20～20KHz

-20

-30

-40

-50

-60

-70

CR OSSTALK(dB)

-80

-90

-100

10 100 1k 10k 100k

FREQUENCY(Hz)

Fig.19

Crosstalk - Frequency

=8Ω,RL_DA=20kΩ,Gain=20dB,fin=1kHz,fs=48kHz)

L_SP

0

Po=1W
L=22µH
C=0.47µF
Cg=0.068µF

FREQUENCY(Hz)

-20

-40

-60

-80

-100

NOISE FFT(dBV)

-120

-140

10 100 1k 10k 100k

FFT of output noise voltage

Po=1W
BW=20～20KHz

FREQUENCY(Hz)

0

-10

-20

-30

-40

-50

-60

-70

CROSSTALK(dB)

-80

-90

-100

0.001 0.01 0.1 1 10 100

Fig.17

THD+N - Frequency

Crosstalk - Output power

Without signal
BW=20～20KHz

FREQUENCY(Hz)

BW=20～20KHz

OUTPUT POWER(W)

Fig.18

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●Pin configuration and Block diagram

1

2

3

4

REG_G1

FILP

Power
Limiter

FILA

5

6

7

REG_3

GNDA

8

I2S/LJ

9

Interface

10

11

12

13

14

15

16

17

18

Control

Interface

I2S/LJ

Selector

Gain

Selector

19

TEST

20

×8 Over
Sampling

Digital

Filter

PWM

Modulator

Driver

1P

Driver

1N

Driver

2N

VCCP1

REG_G1

GNDP1

REG_G1

REG_G2

GNDP2

Technical Note

54

53

NC

52

51

50

49

NC

48

NC

47

46

45

44

43

42

41

NC

40

39

38

37

36

NC

35

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NC

REG_G2

DAC

Selector

DAC

VCCA

High Temperature Protection

Under Voltage Protection

Clock Stop Protection

Output Short Protection

Output DC Voltage Protection

21

22

23

24

25

26

27

6/30

Driver

2P

VCCP2

REG_G2

NC

34

33

32

31

NC

30

29

28

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BD5446EFV

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Technical Note

●Pin function explanation (Provided pin voltages are typ. Values)

No. Pin name Pin voltage Pin explanation Internal equivalence circuit

53,54
28,29

Internal power supply pin for ch1 Gate driver

1

27

REG_G1
REG_G2

5.5V

Internal power supply pin for ch2 Gate driver

1

27

Please connect the capacitor.

45,46
36,37

25

Bias pin for PWM signal

2

FILP 1.75V~2.55V

2

Please connect the capacitor.

6

25

550K

3

4

PLMT 0V Power limiter setting terminal

Bias pin for Analog signal

FILA 2.5V

Please connect the capacitor.

3

400K

6

27

50K

4

50K

6

25

Internal power supply pin for Digital circuit

5

REG3 3.3V

Please connect the capacitor.

6

GNDA 0V GND pin for Analog signal －

5

500K

6

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Technical Note

No. Pin name Pin voltage Pin explanation Internal equivalence circuit

7
8

9
10
11

SYS_CLK

BCLK

LRCLK
SDATA1
SDATA2

0V Digital audio signal input pin

5

7,8,9

10,11

6

50K

12 RESETX

13 MUTEX

14

PDX

0V

15 IIS_LJ 0V

16
17
18

GAIN1
GAIN2
GAIN3

0V

Reset pin for Digital circuit
H: Reset OFF
L: Reset ON

Speaker output mute control pin
H: Mute OFF
L: Mute ON

Power down control pin
H: Power down OFF
L: Power down ON

Digital audio signal data format setting terminal

H: Left Justified format

2

S format

L: I

Gain setting terminal

Gain=20dB~34dB, 2dB step

5

12,13,14

6

5

15

6

5

16,17,18

50K

50K

50K

19
20

TEST1

TEST2

21 SEL_DAC 0V

0V

Test pin

Please connect to GND.

DAC output selection terminal

H: SDATA2 is output from the DAC
L: SDATA1 is output from the DAC

6

5

19,20

50K

6

5

21

50K

6

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Technical Note

No. Pin name Pin voltage Pin explanation Internal equivalence circuit

25

ch2 DAC output pin

22
23

OUT_DAC2

OUT_DAC1

2.5V

ch1 DAC output pin

Please connect it with the latter part circuit
through the capacitor.

22,23

50K

6

25

24 ERROR 3.3V

25 VCCA VCC

26,30
34,35
41,47

N.C. －

48,52

Error flag pin

Please connect pull-up resistor.
H: While Normal
L: While Error

Power supply pin for Analog signal

Non connection pin

24

500

6

－

－

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Technical Note

No. Pin name Pin voltage Pin explanation Internal equivalence circuit

28,29 VCCP2 Vcc Power supply pin for ch2 PWM signal

31,32 OUT2P Vcc~0V

33

BSP2P

－

Output pin of ch2 positive PWM
Please connect to Output LPF.

Boot-strap pin of ch2 positive
Please connect the capacitor.

36,37 GNDP2 0V GND pin for ch2 PWM signal

28,29

33
40

31,32
38,39

38,39 OUT2N Vcc~0V

40 BSP2N －

42 BSP1N －

43,44 OUT1N Vcc~0V

Output pin of ch2 negative PWM
Please connect to Output LPF.

Boot-strap pin of ch2 negative
Please connect the capacitor.

Boot-strap pin of ch1 negative
Please connect the capacitor.

Output pin of ch1 negative PWM
Please connect to Output LPF.

45,46 GNDP1 0V GND pin for ch1 PWM signal

49 BSP1P －

50,51 OUT1P Vcc~0V

Boot-strap pin of ch1 positive
Please connect the capacitor.

Output pin of ch1 positive PWM
Please connect to Output LPF.

36,37

53,54

42
49

43,44
50,51

45,46

53,54 VCCP1 － Power supply pin for ch1 PWM signal

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