ROHM BD37524FS Technical data

Sound Processor Series for Car Audio

Sound Processor with Built-in 3-band Equalizer

BD37524FS

No.10085EAT05

●Description BD37524FS is sound processors built-in 3-band equalizer for car audio. The functions are stereo 5ch input selector, input-gain control, main volume, loudness, 5ch fader volume, LPF for subwoofer, level meter. Moreover, “Advanced switch circuit”, that is ROHM original technology, can reduce various switching noise (ex. No-signal, low frequency likes 20Hz & large signal inputs). “Advanced switch” makes control of microcomputer easier, and can construct high quality car audio system.

●Features

1) Reduce switching noise of input gain control, mute, main volume, fader volume, bass, treble, loudness by using advanced switch circuit [Possible to control all steps]

2) Built-in 1 differential input selector and 4 single-ended input selectors

3) Built-in ground isolation amplifier inputs, ideal for external stereo input.

4) Built-in input gain controller reduces switching noise for volume of a portable audio input.

5) Decrease the number of external components by built-in 3-band equalizer filter, LPF for subwoofer, loudness filter. And, possible to control Q, Gv, fo of 3-band equalizer and fc of LPF, fo, Gv of loudness by I

6) It is possible for the bass, middle, and treble to the gain adjustment quantity of ±20dB and 1 dB step gain adjustment.

7) Terminals for the subwoofer outputs are equipped.

8) Bi-CMOS process is suitable for the design of low current and low energy. And it provides more quality for small scale

regulator and heat in a set.

9) Package is SSOP-A24. Putting input-terminals together and output-terminals together can make PCB layout easier

and can makes area of PCB smaller.

10) It is possible to control by 3.3V / 5V for I

●Applications It is the optimal for the car audio. Besides, it is possible to use for the audio equipment of mini Compo, micro Compo, TV etc with all kinds.

2

C BUS.

2

C BUS control freely

www.rohm.com

1/25

2010.03 - Rev.A

BD37524FS

●Line up matrix

Function Specifications

Input selector

Input gain

Mute ・Possible to use “Advanced switch” for prevention of switching noise.

Volume

Bass

Middle

Treble

Fader

Loudness

LPF

Level meter

●Absolute maximum ratings (Ta=25℃)

・Stereo 4 input ・Differential 1 input ・0～20dB（1dB step）・Possible to use “Advanced switch” for prevention of switching noise.

・+15dB～-79dB（1dB step）, -∞ ・Possible to use “Advanced switch” for prevention of switching noise. ・-20～+20dB（1dB step）・Q=0.5, 1, 1.5, 2 variable ・fo=60, 80, 100, 120Hz ・Possible to use “Advanced switch” at changing gain ・-20～+20dB（1dB step）・Q=0.75, 1, 1.25, 1.5 variable ・fo=500, 1k, 1.5k, 2.5kHz variable ・Possible to use “Advanced switch” at changing gain ・-20～+20dB（1dB step）・Q=0.75, 1.25 variable ・fo=7.5k, 10k, 12.5k, 15kHz variable ・Possible to use “Advanced switch” at changing gain ・+15dB～-79dB(1dB step), -∞dB ・Possible to use “Advanced switch” for prevention of switching noise. ・0dB～20dB(1dB step) ・fo=250/400/800Hz ・Possible to use “Advanced switch” for prevention of switching noise. ・fc=55/85/120/160Hz, pass ・Phase shift (0°/180°) ・I2C BUS control ・DC Output

Technical Note

Item Symbol Rating Unit

Power supply Voltage VCC 10.0 V

Input voltage Vin

Power Dissipation Pd 1000 ※1 mW

Storage Temperature Ta stg -55～+150 ℃

※This value decreases 8mW/℃ for Ta=25℃ or more. ROHM standard board shall be mounted. Thermal resistance θja = 125(℃/W) ROHM Standard board

Size：70×70×1.6(㎣) Material：A FR4 grass epoxy board(3% or less of copper foil area)

●Operating conditions

Item Symbol MIN TYP MAX Unit

Power supply Voltage VCC 7.0 － 9.5 V

Temperature Topr -40 － +85

VCC+0.3～GND-0.3

V

℃

www.rohm.com

2/25

2010.03 - Rev.A

BD37524FS

Technical Note

●Electrical characteristics

(Unless specified particularly, Ta=25℃, VCC=8.5V, f=1kHz, Vin=1Vrms, Rg=600Ω, RL=10kΩ, A1 input, Input gain 0dB, Mute off, Volume 0dB, Tone control 0dB, Loudness 0dB, LPF OFF, Fader 0dB)

Limit

BLOCK

Item Symbol

Min. Typ. Max.

Unit Condition

Current upon no signal IQ － 38 48 mA No signal Voltage gain GV -1.5 0 1.5 dB Gv=20log(VOUT/VIN) Channel balance CB -1.5 0 1.5 dB CB = GV1-GV2 T otal harmonic distortion 1

(FRONT,REAR) T otal harmonic distortion 2

(SUBWOOFER) Output noise voltage 1 (FRONT,REAR)＊ Output noise voltage 2 (SUBWOOFER)＊

GENERAL

THD+N1 － 0.001 0.05 ％ THD+N2 － 0.002 0.05 ％

V

Residual output noise voltage＊ V

－ 3.8 15 μVrms

NO1

－ 4.8 15 μVrms

NO2

－ 1.8 10 μVrms

NOR

VOUT=1Vrms BW=400-30KHz

Rg = 0Ω BW = IHF-A

Fader = -∞dB Rg = 0Ω BW = IHF-A

Rg = 0Ω

Cross-talk between channels＊ CTC － -100 -90 dB

CTC=20log(VOUT/VIN) BW = IHF-A f=1kHz

Ripple rejection RR － -70 -40 dB

VRR=100mVrms

RR=20log(VCC IN/VOUT) Input impedance(A, B) R Input impedance (C,D,E) R

Maximum input voltage VIM 2.1 2.3 － Vrms

70 100 130 kΩ

IN_S

175 250 325 kΩ

IN_D

VIM at THD+N(VOUT)=1％

BW=400-30KHz

Rg = 0Ω Cross-talk between selectors＊ CTS － -100 -90 dB

CTS=20log(VOUT/VIN)

BW = IHF-A

INPUT SELECTOR

Common mode rejection ratio＊ CMRR 50 65 － dB

CP1 and CN input

CP2 and CN input

CMRR=20log(VIN/VOUT)

BW = IHF-A

Input gain 0dB Minimum input gain G

-2 0 +2 dB

IN MIN

VIN=100mVrms

Gin=20log(VOUT/VIN)

Input gain 20dB Maximum input gain G

INPUT GAIN

Gain set error G

18 20 22 dB

IN MAX

VIN=100mVrms

Gin=20log(VOUT/VIN)

-2 0 +2 dB GAIN=+20～+1dB

IN ERR

Mute ON Mute attenuation＊ G

MUTE

－ -105 -85 dB

MUTE

Gmute=20log(VOUT/VIN)

BW = IHF-A

Volume = 15dB Maximum gain G

13 15 17 dB

V MAX

VIN=100mVrms

Gv=20log(VOUT/VIN)

Volume = -∞dB Maximum attenuation＊ G

VOLUME

Attenuation set error 1 G Attenuation set error 2 G Attenuation set error 3

－ -100 -85 dB

V MIN

-2 0 2 dB GAIN & ATT=+15dB～-15dB

-3 0 3 dB ATT=-16dB～-47dB

-4 0 4 dB ATT=-48dB～-79dB

G

V ERR1 V ERR2 V ERR3

Gv=20log(VOUT/VIN)

BW = IHF-A

www.rohm.com

3/25

2010.03 - Rev.A

BD37524FS

BLOCK

Maximum boost gain

BASS

Maximum cut gain

Gain set error

Maximum boost gain

MIDDLE

Maximum cut gain

Gain set error

Maximum boost gain

TREBLE

Maximum cut gain

Gain set error

Maximum boost gain G

Maximum attenuation＊

Gain set error Attenuation set error 1 Attenuation set error 2

FADER / SUBWOOFER

Attenuation set error 3 Output impedance

Maximum output voltage

Maximum gain

LOUDNESS

Gain set error Maximum output voltage V

Level

meter

Output offset voltage V

VP-9690A(Average value detection, effective value display) filter by Matsushita Communication is used for ＊ measurement. Phase between input / output is same.

Item Symbol

G

B BST

G

B CUT

G

B ERR

G

M BST

G

M CUT

G

M ERR

G

T BST

G

T CUT

G

T ERR

F BST

G

F MIN

G

F ERR

G

F ERR1

G

F ERR2

G

F ERR3

R

OUT

V

OM

G

L MAX

G

L ERR

L MAX

L OFF

Min. Typ. Max.

18 20 22 dB

-22 -20 -18 dB

18 20 22 dB

-22 -20 -18 dB

17 20 23 dB

-23 -20 -17 dB

-2 0 2 dB

13 15 17 dB

－

- － 50 Ω VIN=100mVrms

2 2.2

17 20 23 dB

-2 0 2 dB GAIN=+20～+1dB

2.8 3.1 3.5 V －

Limit

Unit Condition

-2 0 2 dB Gain=-20～+20dB f=100Hz

-2 0 2 dB Gain=-20～+20dB f=1kHz

-100 -90 dB

-2 0 2 dB Gain=+1～+15dB

-2 0 2 dB ATT=-1～-15dB

-3 0 3 dB

-4 0 4 dB ATT=-48～-79dB

－

Vrms

0 100 mV

Technical Note

Gain=+20dB f=100Hz VIN=100mVrms GB=20log (VOUT/VIN)

Gain=-20dB f=100Hz VIN=2Vrms GB=20log (VOUT/VIN)

Gain=+20dB f=1kHz VIN=100mVrms GM=20log (VOUT/VIN) Gain=-20dB f=1kHz VIN=2Vrms GM=20log (VOUT/VIN)

Gain=+20dB f=10kHz VIN=100mVrms GT=20log (VOUT/VIN)

Gain=-20dB f=10kHz VIN=2Vrms G

=20log (VOUT/VIN)

T

Gain=-20～+20dB f=10kHz Fader=15dB

V

=100mVrms

IN

G

=20log(VOUT/VIN)

F

Fader = -∞dB G

=20log(VOUT/VIN)

F

BW = IHF-A

ATT=-16～-47dB

THD+N=1％ BW=400-30KHz Gain 20dB VIN=100mVrms G

=20log(VOUT/VIN)

L

www.rohm.com

4/25

2010.03 - Rev.A

BD37524FS

%

u

dB

●Electrical characteristic curves (Reference data)

Technical Note

50

40

30

Iq[mA]

20

10

0

0246810

VCC[V]

Fig.1 Iq vs Vcc

25 20 15 10

5

Gain[dB]

0

-5

-1 0

-1 5

-2 0

-2 5 10 100 1k 10k 100k

BASS GAIN : -20～+20dB /1dB step fo : 60Hz Q : 0.5

Frequency [Hz]

Fig.4 Bass Gain vs Freq

25 20 15 10

5 0

-5

Gain[dB]

-1 0

-1 5

-2 0

-2 5

10 100 1k 10k 100k

MIDDLE GAIN :

-20～+20dB /1dB step

Frequency [Hz]

fo : 500Hz Q : 0.75

Fig.7 Middle Gain vs Freq

10

1

0.1

THD+N (

THD+N[%]

0.01

0.001

0.0 0 1 0 .0 1 0.1 1 10

25 20 15 10

5

Gain[dB]

0

-5

-1 0

-1 5

-2 0

-2 5 10 100 1k 10k 100k

Vout [Vrms]

Fig.2 Thd vs Vo

Frequency [Hz]

Fig.5 Bass fo vs Freq

25 20 15 10

5 0

-5

Gain[dB]

-1 0

-1 5

-2 0

-2 5 10 100 1k 10k 100k

Frequency [Hz]

Fig.8 Middle fo vs Freq Fig.9 Middle Q vs Freq

10kHz

1kHz

100Hz

Vout (V)

fo : 60/80/100/120Hz BASS GAIN : ±20dB Q : 0.5

fo : 500/1k/1.5k/2.5kHz

10

1

0.1

0.01

0.001

5 4 3

Vo

Vin[Vrms]

2 1 0

Gain[dB]

Gain (

-1

10 100 1k 10k 100k

-2

-3

-4

-5

Fig.3 Gain vs Freq

Fig.12 Gain vs Freq

25 20 15 10

5 0

Gain[dB]

-5

-1 0

-1 5

-2 0

-2 5 10 100 1k 10k 100k

Gain=0dB

Frequency [Hz]

Frequency (Hz)

Q : 0.5/1/1.5/2 BASS GAIN : ±20dB fo : 60Hz

Frequency [Hz]

Fig.6 Bass Q vs Freq

25 20 15 10

5 0

-5

Gain[dB]

-10

-15

-20

-25 10 100 1k 10k 100k

Q : 0.75/1/1.25/1.5

Frequency [Hz]

MIDDLE GAIN : ±20dB fo : 1kHz

25

TREBLE GAIN:-20～+20dB

20

/1dB step fo : 7.5kHz Q : 0. 75

15 10

5 0

-5

Gain (dB)

Gain[dB]

-10

-15

-20

-25 10 100 1k 10k 100k

Frequency [Hz]

Frequency (Hz)

25

fo : 7.5k/10k/12.5k/15kHz TREBLE GAIN : ±20dB

20

Q : 0.75

15 10

5 0

Output

-5

Noise[uVrm

-10

-15

-20

-25 10 100 1k 10k 100k

Frequency [Hz]

Fig.10 Treble Gain vs Freq Fig.11 Treble fo vs Freq Fig.12 Treble Q vs Freq

www.rohm.com

5/25

25

Q : 0.75/1.25

20

TREBLE GAIN : ±20dB fo : 7.5kHz

15 10

5 0

-5

Gain (dB)

Gain[dB]

-10

-15

-20

-25 10 100 1k 10k 100k

Frequency [Hz]

Frequency (Hz)

2010.03 - Rev.A

BD37524FS

B

g

1000

100

Din-Audio IHF-A

1000

100

DIN-Audio IHF-A

Technical Note

1000

DIN-Audio IHF-A

100

10

Output Noise[uVrms]

出力雑音電圧[uVrms]

1

-80 -70 -60 -50 -40 -30 -20 -10 0 10 20

Volume Gain[dB]

Fig.13 Volume Gain vs Noise

1000

DIN-Audio IHF-A

100

10

Output Noise[uVrms]

出力雑音電圧 [uVrms]

1

-20 -15 -10 -5 0 5 10 15 20 Treble Gain [dB]

Fig.16 Treble Gain vs Noise

10

Output Noise[uVrms]

出力雑音電圧 [uVrms]

1

-20 -15 -10 -5 0 5 10 15 20

0

-1 0

-2 0

-3 0

Gain[dB]

-4 0

Gain (d

-5 0

-6 0

-7 0 10 100 1k 10k 100k

Bass Gain [dB]

.14 Bass Gain vs Noise

Fi

Frequency [Hz]

Frequency (Hz)

Fig.17 CMRR vs Freq

10

出力雑音電圧 [uVrms]

1

-20 -15 -10 -5 0 5 10 15 20 Middle Gain [dB]

Fig.15 Middle Gain vs Noise

2.5

2.0

1.5

1.0

Vo [Vrms]

最大出力[Vrms]

0.5

0.0 100 1000 10000 100000

Rload [ohm]

出力負荷[ohm]

Fig.18 Rload vs Vo

3.5

3

2.5

2

1.5

Vout[V]

1

0.5

0

00.511.522.53

Vin [Vrms]

Fig.19 Advanced Switch 1

Fig.20 Advanced Switch 2 Fig.21 Level Meter Vin vs Vo

www.rohm.com

6/25

2010.03 - Rev.A

BD37524FS

●Block diagram and pin configuration

GND

I2C BUS LOGIC

VCC

■Fader Gain:+15dB～-79ｄB/1dB step

★no pop noise

■LPF fc=55/85/120/160Hz

■Loudness Gain:20dB～0ｄB/1ｄB step

★no pop noise

・ｆ0=250/400/800Hz ・Hicut:1/2/3/4

■3 Band P-EQ (Tone control) Gain：+20dB～-20dB/1dB step

★no pop noise

・Bass：f0=60/80/100/120Hz

Q=0.5/1.0/1.5/2.0

・Meddle:f0=500/1k/1.5k/2.5kHz

Q=0.75/1/1.25/1.5

・Treble：f0=7.5k/10k/12.5k/15kHz

Q=0.75/1.25

■Volume Gain：+15dB～-79dB/1dB step

★no pop noise

■Input Gain Gain：+20dB～0dB/1dB step

★no pop noise

Fader★

★Loudness

★3 Band P-EQ

(Tone control)

★Volume/Mute

★Input Gain

Input selector (4 single-end and 1 stereo ISO)

VCC/2

100k 100k 100k 100k 250k

1 2 3 4 5 6 7 8

ISO amp

Fig.22 BD37524FS

Descriptions of terminal

Terminal

No.

Terminal

Name

Description

1 FIL VCC/2 terminal 13 MUTE External compulsory mute terminal 2 A1 A input terminal of 1ch 14 LOUT Output terminal for Level meter 3 A2 A input terminal of 2ch 15 OUTS2 Subwoofer output terminal of 2ch 4 B1 B input terminal of 1ch 16 OUTS1 Subwoofer output terminal of 1ch 5 B2 B input terminal of 2ch 17 OUTR2 Rear output terminal of 2ch 6 CP1 C positive input terminal of 1ch 18 OUTR1 Rear output terminal of 1ch 7 CN C negative input terminal 19 OUTF2 Front output terminal of 2ch 8 CP2 C positive input terminal of 2ch 20 OUTF1 Front output terminal of 1ch

9 D1 D input terminal of 1ch 21 VCC Power supply terminal 10 D2 11 E1 12 E2

D input terminal of 2ch E input terminal of 1ch E input terminal of 2ch

GND

Technical Note

14

1324 23 22 21 20 19 18 17 16 15

Fader★

GND

ISO amp

250k250k 250k 250k 250k 250k

Terminal

No.

22 SCL I2C Communication clock terminal 23 SDA I2C Communication data terminal 24 GND GND terminal

Fader★

LPF

9

Terminal

Name

Level meter

10 11 12

Description

www.rohm.com

7/25

2010.03 - Rev.A

BD37524FS

Technical Note

●Timming Chart

CONTROL SIGNAL SPECIFICATION

(１) Electrical specifications and timing for bus lines and I/O stages

SDA

SCL

t

BUF

t

LOW

t

R

F

t

HD;STA

t

SP

P

t

HD;STA

S

t

HD;DAT

t

HIGH

t

SU;D AT tSU;STA

Sr

t

SU;STO

2

Fig.23 Definition of timing on the I

Table 1 Characteristics of the SDA and SCL bus lines for I

2

C-bus devices

C-bus

(Unless specified particularly, Ta=25℃, VCC=8.5V)

Parameter Symbol

Fast-mode I2C-bus

Min. Max.

1 SCL clock frequency ｆSCL 0

400 kHz

2 Bus free time between a STOP and START condition tBUF 1.3 － μS

Hold time (repeated) START condition. After this period, the first

3

clock pulse is generated

tHD;STA 0.6 － μS

4 LOW period of the SCL clock tLOW 1.3 － μS 5 HIGH period of the SCL clock tHIGH 0.6 － μS 6 Set-up time for a repeated START condition tSU;STA 0.6 － μS 7 Data hold time: tHD;DAT 0.06* － μS 8 Data set-up time tSU;DAT 120 － ns 9 Set-up time for STOP condition tSU;STO 0.6 － μS

All values referred to VIH min. and VIL max. Levels (see Table 2).

* A device must internally provide a hold time of at least 300 ns for the SDA signal (referred to the VIH min. of the SCL

signal) in order to bridge the undefined region of the falling edge of SCL.

About 7(tHD;DAT), 8(tSU;DAT), make it the setup which a margin is fully in .

P

Unit

www.rohm.com

8/25

2010.03 - Rev.A