Datasheet LC75421M Datasheet (SANYO)

Ordering number : ENN6866A

90503TN (OT) / 20901RM (OT) No. 6866-1/24

Overview

The LC75421M is an electronic volume controller that
enables control of volume, balance, fader, bass/treble +
super bass, input switching, and input and output level
control functions using only a small number of external
components.

Functions

• Volume:

0 dB to –79 dB in 1-dB steps, and –∞ (81 positions)
Balance function with separate L/R control

• Fader: rear output or front output can be attenuated
across 16 positions (in 2-dB steps from 0 dB to ­20 dB, 5-dB steps from –20 dB to –25 dB, 10-dB
steps from –25 dB to –45 dB, and –60 dB, –∞)

• Bass/treble: A tone control circuit can be configured

using an external RC, with 15-position
control from 0 dB to ±11.9 dB in 1.7-dB
steps possible for both bass and treble

• Input gain: 0 dB to +18.75 dB (1.25-dB steps)

amplification is possible for the input signal.

• Output gain: Fader output can be selected among 0 dB,

+6.5 dB, and +8.5 dB.

• Input switching: Five input signals can be selected for

Left and for Right

• Super bass: Step control with 11 positions is possible,

with peaking characteristics (type T)

Features

• On-chip buffer amplifier cuts down number of external
components

• Low switching noise generated by on-chip switch due to
use of silicon gate CMOS process

• On-chip reference voltage circuit for analog ground

• Controls performed with serial input (CCB)

Package Dimensions

unit: mm

3263-MFP36SDJ (375 mil)

1

18

36 19

0.8

15.2

0.3

0.65

10.5

7.9

0.25

(0.8)

2.45max

0.1

(2.25)

SANYO: MFP36SDJ (375 mil)

[LC75421M]

LC75421M

SANYO Electric Co.,Ltd. Semiconductor Company

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN

Electronic Volume Controller for Cars

CMOS IC

Any and all SANYO products described or contained herein do not have specifications that can handle
applications that require extremely high levels of reliability, such as life-support systems, aircraft’s
control systems, or other applications whose failure can be reasonably expected to result in serious
physical and/or material damage. Consult with your SANYO representative nearest you before using
any SANYO products described or contained herein in such applications.

SANYO assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other
parameters) listed in products specifications of any and all SANYO products described or contained
herein.

• CCB is a trademark of SANYO ELECTRIC CO., LTD.

• CCB is SANYO’s original bus format and all the bus
addresses are controlled by SANYO.

Pin Assignment

No. 6866-2/24

LC75421M

LC75421M

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18

36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19

DI

CE

VSS

LROUT

LFOUT

LFIN

LOUT

LSB
LBASS2
LBASS1

LTRE

LIN

LSELO

L5
L4
L3
L2
L1

CL
VDD
RROUT
RFOUT
RFIN
ROUT
RSB
RBASS2
RBASS1
RTRE
RIN
RSELO
R5
R4
R3
R2
R1
Vref

Top view

No. 6866-3/24

LC75421M

Equivalent Circuit Block Diagram

2.2 µF

2.2 µF

µCOM

2.2 µF

VDD

VSS

CE

DI

CL

2.2 µF

PA

PA

PA

PA

LROUT

4

3 2 1 36 35

RROUT

RFOUT

RFIN

ROUT

1 µF

1 µF

0.15 µF

0.15 µF

3.7 kΩ

RSB
RBASS2

34

33

32

31

30

0.082 µF

0.082 µF

7.68 kΩ

1500 pF

RBASS1

Control

circuit

RVref

LVref

Control

circuit

CCB

interface

Control

circuit

RTRE

RIN

RSELO

29

28

27

25

26

5

6

7

8

9

10

11

12

13

14

1 µF

L5

1 µFL41 µFL31 µFL21 µF

L1

22 µF

Vref

1 µFR11 µF

R2

1 µFR31 µF

R4

1 µF

R5

15 16 17 18 19 20 21 22 23 24

LFOUT

LFIN

LSB

LBASS2

LBASS1

LTRE

LIN

LSELO

0.15 µF

1500 pF

1 µF

0.15 µF

0.082 µF

0.082 µF

1 µF

LOUT

3.7 kΩ

7.68 kΩ

[TREBLE f0 10 kHz] [BASS f0 100 Hz] [S-BASS f0 68 Hz]

No. 6866-4/24

LC75421M

Parameter Symbol Conditions Ratings Unit

Maximum supply voltage V

DD

max V

DD

11 V

Maximum input voltage V

IN

max

CE, DI, CL –0.3 to 11

V

Input pins other than CE, DI, CL V

SS

– 0.3 to VDD+ 0.3
Allowable power dissipation Pdmax Ta ≤ 85°C, when mounted on board 550 mW
Operating temperature Topr –40 to +85 °C
Storage temperature Tstg –50 to +125 °C

Specifications

Absolute Maximum Ratings at Ta = 25°C, VSS= 0 V

Parameter Symbol Pin Name Conditions

Ratings

Unit

min typ max

Supply voltage V

DDVDD

7.5 10 V

Input high-level voltage V

IH

CL, DI, CE 4.0 10 V

Input low-level voltage V

IL

CL, DI, CE V

SS

1.0 V

CL, DI, CE, LIN, RIN,

Input amplitude voltage V

IN

L1 to L5, R1 to R5, V

SS

V

DD

Vp-p

LFIN, RFIN
Input pulse width tøW CL 1 µs
Setup time tsetup CL, DI, CE 1 µs
Hold time thold CL, DI, CE 1 µs
Operating frequency fopg CL 500 kHz

Allowable Operating Ranges at Ta = –40 to +85°C, VSS= 0 V

Parameter Symbol Pin Name Conditions

Ratings

Unit

min typ max
Maximum input gain Ginmax +18.75 dB
Step resolution Gstep +1.25 dB

Input resistance Rin

L1, L2, L3, L4, L5

50 kΩ

R1, R2, R3, R4, R5
Clipping level Vcl LSELO, RSELO THD = 1.0%, f = 1 kHz 2.90 Vrms
Output load resistance RL LSELO, RSELO 10 kΩ

Electrical Characteristics at Ta = 25°C, VDD= 8 V, VSS= 0 V

Parameter Symbol Pin Name Conditions

Ratings

Unit

min typ max

Input resistance Rin LIN, RIN 50 kΩ

Volume Block

Parameter Symbol Pin Name Conditions

Ratings

Unit

min typ max

STEP = 0 dB to –20 dB 2

Step resolution ATstep STEP = –20 dB to –25 dB 5 dB

STEP = –25 dB to –45 dB 10

Step error ATerr

STEP = 0 dB to –45 dB –2 0 +2

dB

STEP = –45 dB to –60 dB –3 0 +3

Output load resistance RL 10 kΩ
Output impedance R

O

LFOUT, LROUT RL = 10 kΩ, f = 1 kHz

46 Ω

RFOUT, RROUT V

IN

= 1 Vrms

Fader Volume Block

No. 6866-5/24

LC75421M

Parameter Symbol Pin Name Conditions

Ratings

Unit

min typ max
Control range Gbass MAX. Boost/Cut ±10 ±11.9 ±14 dB
Step resolution Estep 1 1.7 3 dB
Internal feedback resistance Rfeed 45.084 kΩ

Bass Band Control Block

Parameter Symbol Pin Name Conditions

Ratings

Unit

min typ max
Control range Gtre MAX. Boost/Cut ±10 ±11.9 ±14 dB
Step resolution Estep 1 1.7 3 dB
Internal feedback resistance Rfeed 56.084 kΩ

Treble Band Control Block

Parameter Symbol Pin Name Conditions

Ratings

Unit

min typ max
Control range Crange MAX. Boost +20 dB
Step resolution Estep +2.0 dB
Internal feedback resistance Rfeed 66.6 kΩ

Super Bass Block (Type T)

Parameter Symbol Conditions

Ratings

Unit

min typ max
Total harmonic distortion THD V

IN

= 1 Vrms, f = 1 kHz, flat overall 0.003 0.01 %

Crosstalk CT V

IN

= 1 Vrms, f = 1 kHz, flat overall, Rg = 1 kΩ 80.5 dB

Maximum attenuated output Vomin V

IN

= 1 Vrms, f = 1 kHz, main volume –∞ –80 dB

Output noise voltage

VN-1 Fflat overall, (IHF-A), RG = 1 kΩ 8 µV
VN-2 Flat overall, (DIN-AUDIO), RG = 1 kΩ 10 µV

Input high-level current I

IH

CL, DI, CE VIN= 8 V 10 µA

Input low-level current I

IL

CL, DI, CE VIN= 0 V –10 µA

General

Control Timing and Data Format

To control the LC75421M, input specified serial data to the CE, CL, and DI pins.
The data configuration consists of a total of 52 bits broken down into 8 address bits and 44 data bits.

No. 6866-6/24

LC75421M

CE

B0 B1 B2 B3 A0 A1 A2 A3

1 µs

min

1 µs

min

1 µs

min

1 µs ≤ T

DEST

B
0

D0D1D2D3D4D5D6D7D8D9D10D11D12D13D14D15D16D17D18D19D20D21D22D

23

0
1

0
1

D24D25D26D27D28D29D30D31D32D33D34D35D36D37D38D39D40D41D42D

43

B1B2B3A0A1A2A

3

1 0 0 0 0 0 0 1

1 µs

min

1 µs

min

D0 D1 D2 D3 D4 D5

D38 D39 D40 D41 D42 D43

DI

DI

Super bass control

Treble control

Boost

Boost

Caution: Be sure to set D36 to D38 and D40 to D43

to “0” for the TEST bit of the IC.

CL

CL

CE

Address code

Fader step control

0 0 0 0
1 0 0 0
0 1 0 0
1 1 0 0
0 0 1 0
1 0 1 0
0 1 1 0
1 1 1 0
0 0 0 1
1 0 0 1
0 1 0 1
1 1 0 1
0 0 1 1
1 0 1 1
0 1 1 1
1 1 1 1

–∞ dB
–60 dB
–45 dB
–35 dB
–25 dB
–20 dB
–18 dB
–16 dB
–14 dB
–12 dB
–10 dB

–8 dB
–6 dB
–4 dB
–2 dB

0 dB

0 0 0 0
1 0 0 0
0 1 0 0
1 1 0 0
0 0 1 0
1 0 1 0
0 1 1 0
1 1 1 0
0 0 0 1
1 0 0 1
0 1 0 1
1 1 0 1
0 0 1 1
1 0 1 1
0 1 1 1
1 1 1 1

0 dB
+1.25 dB
+2.50 dB
+3.75 dB
+5.00 dB
+6.25 dB
+7.50 dB
+8.75 dB

+10.00 dB
+11.25 dB
+12.50 dB
+13.75 dB
+15.00 dB
+16.25 dB
+17.50 dB
+18.75 dB

0 0
0 1
1 0
1 1

0 0
1 0
0 1
1 1

0 dB

0 dB
+6.5 dB
+8.5 dB

1 1 1 0
0 1 1 0
1 0 1 0
0 0 1 0
1 1 0 0
0 1 0 0
1 0 0 0
0 0 0 0
1 0 0 1
0 1 0 1
1 1 0 1
0 0 1 1
1 0 1 1
0 1 1 1
1 1 1 1

STEP15
STEP14
STEP13
STEP12
STEP11
STEP10
STEP9
STEP8
STEP7
STEP6
STEP5
STEP4
STEP3
STEP2
STEP1
Cut

1 1 1 0
0 1 1 0
1 0 1 0
0 0 1 0
1 1 0 0
0 1 0 0
1 0 0 0
0 0 0 0
1 0 0 1
0 1 0 1
1 1 0 1
0 0 1 1
1 0 1 1
0 1 1 1
1 1 1 1

STEP15
STEP14
STEP13
STEP12
STEP11
STEP10
STEP9
STEP8
STEP7
STEP6
STEP5
STEP4
STEP3
STEP2
STEP1
Cut

0 0 0 0
1 0 0 0
0 1 0 0
1 1 0 0
0 0 1 0
1 0 1 0
0 1 1 0
1 1 1 0
0 0 0 1
1 0 0 1
0 1 0 1

STEP0(FLAT)
STEP1
STEP2
STEP3
STEP4
STEP5
STEP6
STEP7
STEP8
STEP9
STEP10

(BOOST max)

Bass control

Volume control

Fader
rear/front
control

Rear
Front

OFF

ON

TEST mode

Input switch control (1) Input switch control (2)

Input mute
switch control

Input gain control

Channel selection

Initial setting
Lch
Rch
L/R simultaneous

Output gain control

No. 6866-7/24

LC75421M

Volume Control

D16 D17 D18 D19 D20 D21 D22 D23 Operation

0 0 1 0 0 1 0 1 0dB
1 1 0 0 0 1 0 1 –1dB
0 1 0 0 0 1 0 1 –2dB
1 0 0 0 0 1 0 1 –3dB
0 0 1 1 1 0 0 1 –4dB
1 1 0 1 1 0 0 1 –5dB
0 1 0 1 1 0 0 1 –6dB
1 0 0 1 1 0 0 1 –7dB
0 0 1 0 1 0 0 1 –8dB
1 1 0 0 1 0 0 1 –9dB

0 1 0 0 1 0 0 1 –10dB
1 0 0 0 1 0 0 1 –11dB
0 0 1 1 0 0 0 1 –12dB
1 1 0 1 0 0 0 1 –13dB
0 1 0 1 0 0 0 1 –14dB
1 0 0 1 0 0 0 1 –15dB
0 0 1 0 0 0 0 1 –16dB
1 1 0 0 0 0 0 1 –17dB
0 1 0 0 0 0 0 1 –18dB
1 0 0 0 0 0 0 1 –19dB
0 0 1 1 1 1 1 0 –20dB
1 1 0 1 1 1 1 0 –21dB
0 1 0 1 1 1 1 0 –22dB
1 0 0 1 1 1 1 0 –23dB
0 0 1 0 1 1 1 0 –24dB
1 1 0 0 1 1 1 0 –25dB
0 1 0 0 1 1 1 0 –26dB
1 0 0 0 1 1 1 0 –27dB
0 0 1 1 0 1 1 0 –28dB
1 1 0 1 0 1 1 0 –29dB
0 1 0 1 0 1 1 0 –30dB
1 0 0 1 0 1 1 0 –31dB
0 0 1 0 0 1 1 0 –32dB
1 1 0 0 0 1 1 0 –33dB
0 1 0 0 0 1 1 0 –34dB
1 0 0 0 0 1 1 0 –35dB
0 0 1 1 1 0 1 0 –36dB
1 1 0 1 1 0 1 0 –37dB
0 1 0 1 1 0 1 0 –38dB
1 0 0 1 1 0 1 0 –39dB
0 0 1 0 1 0 1 0 –40dB
1 1 0 0 1 0 1 0 –41dB
0 1 0 0 1 0 1 0 –42dB
1 0 0 0 1 0 1 0 –43dB
0 0 1 1 0 0 1 0 –44dB
1 1 0 1 0 0 1 0 –45dB
0 1 0 1 0 0 1 0 –46dB
1 0 0 1 0 0 1 0 –47dB
0 0 1 0 0 0 1 0 –48dB
1 1 0 0 0 0 1 0 –49dB
0 1 0 0 0 0 1 0 –50dB

Continued on next page.

No. 6866-8/24

LC75421M

Continued from preceding page.

D16 D17 D18 D19 D20 D21 D22 D23 Operation

1 0 0 0 0 0 1 0 –51dB
0 0 1 1 1 1 0 0 –52dB
1 1 0 1 1 1 0 0 –53dB
0 1 0 1 1 1 0 0 –54dB
1 0 0 1 1 1 0 0 –55dB
0 0 1 0 1 1 0 0 –56dB

1 1 0 0 1 1 0 0 –57dB
0 1 0 0 1 1 0 0 –58dB
1 0 0 0 1 1 0 0 –59dB
0 0 1 1 0 1 0 0 –60dB
1 1 0 1 0 1 0 0 –61dB
0 1 0 1 0 1 0 0 –62dB
1 0 0 1 0 1 0 0 –63dB
0 0 1 0 0 1 0 0 –64dB
1 1 0 0 0 1 0 0 –65dB
0 1 0 0 0 1 0 0 –66dB
1 0 0 0 0 1 0 0 –67dB
0 0 1 1 1 0 0 0 –68dB
1 1 0 1 1 0 0 0 –69dB
0 1 0 1 1 0 0 0 –70dB
1 0 0 1 1 0 0 0 –71dB
0 0 1 0 1 0 0 0 –72dB
1 1 0 0 1 0 0 0 –73dB
0 1 0 0 1 0 0 0 –74dB
1 0 0 0 1 0 0 0 –75dB
0 0 1 1 0 0 0 0 –76dB
1 1 0 1 0 0 0 0 –77dB
0 1 0 1 0 0 0 0 –78dB
1 0 0 1 0 0 0 0 –79dB
0 0 0 0 0 0 0 0 –∞dB

Input Switch Control (L1, L2, L3, L4, L5, R1, R2, R3, R4, R5)

D28 D29 D32 Operation

0 0 1 L1 (R1) ON
1 0 1 L2 (R2) ON
0 1 1 L3 (R3) ON
1 1 1 L4 (R4) ON
0 0 0 L5 (R5) ON

No. 6866-9/24

LC75421M

Pin Functions

Pin No. Pin Name Function Equivalent circuit

• Input signal pins

18
17
16
15
14
20
21
22
23
24

L1
L2
L3
L4

L5
R1
R2
R3
R4
R5

VDD

VDD

SELO

Ln
Rn

Vref

VDD

VDDVDD

BASS1 BASS2

• Input selector output pins

13
25

LSELO
RSELO

• Bass band filter configuration capacitor and resistor
connection pins

10

9
28
29

LBASS1
LBASS2
RBASS1
RBASS2

VDD

VDDVDD

SB OUT

• Super bass band filter configuration capacitor and resistor
connection pins

8

7
30
31

LSB

LOUT

RSB

ROUT

VDD

• Fader output pins. The front side and rear side can be
attenuated separately. The attenuation is the same for both
Left and Right.

5

4
33
34

LFOUT
LROUT
RFOUT

RROUT

Continued on next page.

No. 6866-10/24

LC75421M

Continued from preceding page.

Pin No. Pin Name Function Equivalent circuit

• Capacitor connection pin for configuring treble filter

11
27

LTRE

RTRE

VDD

TRE

• Connect a capacitor of a few tens of µF between Vref and
AV

SS(VSS

) as a analog ground 0.5 × VDDvoltage

generator, current ripple countermeasure.

19 Vref

VDD

Vref

VDD

• Ground pin 3

V

SS

• Power supply pin35

V

DD

• Chip enable pin
Data is written to the internal latch and the analog switches

are operated when the level changes from High to Low.
Data transfer is enabled when the level is High.

2 CE

• Serial data pin and clock input pin for control

1

36

DI

CL

No. 6866-11/24

LC75421M

Equivalent Circuit Input Block Diagram

L1

LSEL0

TOTAL = 50 k

LVref

Same for right channel
Unit: (Resistance: Ω)

6.702 k

0 dB

5.804 k

+1.25 dB

5.026 k

+2.50 dB

4.352 k

+3.75 dB

3.769 k

+5.00 dB

3.264 k

+6.25 dB

2.826 k

+7.50 dB

2.447 k

+8.75 dB

2.119 k

+10.00 dB

1.835 k

+11.25 dB

1.589 k

+12.50 dB

1.376 k

+13.75 dB

1.192 k

+15.00 dB

1.032 k

+16.25 dB

0.894 k

+17.50 dB

5.774 k

+18.75 dB

L2

L3

L4

L5

50 k

50 k

50 k

50 k

50 k

No. 6866-12/24

LC75421M

Volume Block Equivalent Circuit Diagram

LIN

R1 = 5434

0 dB

R2 = 4845

–1 dB

R3 = 4319

–2 dB

R4 = 3850

–3 dB

R5 = 3431

–4 dB

R6 = 3058

–5 dB

R7 = 2726

–6 dB

R8 = 2429

–7 dB

R9 = 2165

–8 dB

R10 = 1930

–9 dB

R11 = 1720

–10 dB

R12 = 1533

–11 dB

R13 = 1366

–12 dB

R14 = 1218

–13 dB

R15 = 1085

–14 dB

R16 = 967

–15 dB

R17 = 862

–16 dB

R18 = 768

–17 dB

R19 = 685

–18 dB

R20 = 610

–19 dB

R21 = 544

–20 dB

R22 = 485

–21 dB

R23 = 432

–22 dB

R24 = 385

–23 dB

R25 = 343

–24 dB

R26 = 306

–25 dB

R27 = 273

–26 dB

R28 = 243

R29 = 216

–28 dB

R30 = 193

–29 dB

R31 = 172

–30 dB

R32 = 153

–31 dB

R33 = 137

–32 dB

R34 = 122

–33 dB

R35 = 108

–34 dB

R36 = 97

–35 dB

R37 = 86

–36 dB

R38 = 77

–37 dB

R39 = 68

–38 dB

R40 = 61

–39 dB

R41 = 54

–40 dB

R42 = 48

–41 dB

R43 = 86

–42 dB

R44 = 77

–43 dB

R45 = 69

–44 dB

R46 = 61

–45 dB

R47 = 55

–46 dB

R48 = 49

–47 dB

R49 = 87

–48 dB

R50 = 77

–49 dB

R51 = 69

–50 dB

R52 = 61

–51 dB

R53 = 55

–52 dB

R54 = 49

–53 dB

–54 dB

794
R81

796
R82

798
R83

800
R84

802
R85

804
R86

Same for right channel
Unit: (Resistance: Ω)

LVref

R55 = 87

R56 = 77

–55 dB

To
Treble
Block

R57 = 69

–56 dB

R58 = 61

–57 dB

R59 = 55

–58 dB

R60 = 49

–59 dB

R61 = 87

–60 dB

R62 = 78

–61 dB

R63 = 69

–62 dB

R64 = 62

–63 dB

R65 = 55

–64 dB

R66 = 49

–65 dB

R67 = 87

–66 dB

R68 = 78

–67 dB

R69 = 69

–68 dB

R70 = 62

–69 dB

R71 = 55

–70 dB

R72 = 49

–71 dB

R73 = 87

–72 dB

R74 = 78

–73 dB

R75 = 69

–74 dB

R76 = 62

–75 dB

R77 = 55

–76 dB

R78 = 49

–77 dB

R79 = 44

–78 dB

R80 = 359

–79 dB

–∞ dB

–27 dB

No. 6866-13/24

LC75421M

Treble/Bass/Super Bass Band Block Equivalent Circuit Diagram

From
Volume
Block

Same for right channel
Unit: (Resistance: Ω)

SW1

LTRE

Total = 56.084 k

±11.9 dB11.030 k

±10.2 dB

±8.5 dB

±6.8 dB

±5.1 dB

±3.4 dB

±1.7 dB

0 dB

2.908 k

3.661 k

4.608 k

5.802 k

7.304 k

9.195 k

11.576 k

LSB

During boost, SW1 and SW3 are ON, during cut, SW2 and SW4 are ON,
when 0 dB, 0 dB SW and SW2 and SW3 are ON.

Total = 66.6 k

+18 dB

+4 dB

+2 dB

0 dB

+20 dB

+16 dB

+14 dB

+12 dB

+10 dB

+8 dB

±6 dB

1.916 k

2.412 k

3.037 k

3.823 k

4.813 k

6.059 k

7.628 k

9.603 k

12.089 k

15.220 k

SW2

SW3

SW4

SW1

LBASS1

LOUT

LBASS2Total = 45.084 k

±11.9 dB0.030 k

±10.2 dB

±8.5 dB

±6.8 dB

±5.1 dB

±3.4 dB

±1.7 dB

0 dB

2.908 k

3.661 k

4.608 k

5.802 k

7.304 k

9.195 k

11.576 k

SW2

SW3

SW4

Same for right channel
Units: (Resistance: Ω)

No. 6866-14/24

LC75421M

Fader Volume Block Equivalent Circuit Diagram

LFIN

S1

S2

0 dB

26.342 k

4.866 k
50 k

18.792 k

+6.5 dB

+8.5 dB

0 dB

26.342 k

4.866 k

50 k

18.792 k

Same for right channel
Unit: (Resistance: Ω)

When FADER = “1”, S2 and S3 are ON
When FADER = “0”, S1 and S4 are ON

Total = 50 k

+6.5 dB

+8.5 dB

S4

S3

LFOUT LROUT

LVref

When –∞ data is sent to the main volume, S1 and S2 become open, and S3 and S4 simultaneously become ON.

10.284 k

8.169 k

6.489 k

5.154 k

4.094 k

3.252 k

2.583 k

2.052 k

1.630 k

1.295 k

2.188 k

1.923 k

0.608 k

0.231 k

0.050 k

0 dB

–2 dB

–4 dB

–6 dB

–8 dB

–10 dB

–12 dB

–14 dB

–16 dB

–18 dB

–20 dB

–25 dB

–35 dB

–45 dB

–60 dB

–∞ dB

Tone Circuit Constant Calculation Examples

Super Bass Band Circuit

The equivalent circuit and the formula for calculating the external RC with a mean frequency of 68 Hz are shown
below.

• Super bass band equivalent circuit block diagram

• Calculation example
Specification Mean frequency: f0 = 68 Hz

Gain during maximum boost: G = 20 dB
Let us use R1 = 0, R2 = 66.6 kΩ, and C1 = C2 = C.

We obtain R3 from G = 20 dB.

We obtain C from mean frequency f0 = 68 Hz.

We obtain Q.

No. 6866-15/24

LC75421M

C1

R1 R2

R3

C2

G

+20 dB

= 20 × LOG10 1 +

R2

2R3

R3 =

R2

2 10

G+20dB/20

–1

66600

2

× (10 – 1)

= ≠ 3.7 KΩ

f 0 =

R3R2C1C2

1

2π

C = =

1

2

πf0 R3R2

1

2π × 68 66600 × 3700

≠ 0.15 µF

Q =

R3R2

R3R2

2R3

1

≠ 2.1

Treble Band Circuit

The shelving characteristics can be obtained for the treble band.
The equivalent circuit and calculation formula during boost are indicated below.

• Calculation example 1
Specification Set frequency: f = 10000 Hz

Gain during maximum boost: G

+ 14 dB

= 14 dB

Let us use R1 = 11.030 kΩ and R2 = 45.054 kΩ.
The above constants are inserted in the following formula.

No. 6866-16/24

LC75421M

C

R1 R2

C =

R2

)

2

– R1

2

1

2

πf

10

G/20

– 1

(

=

1

2

π10000

45054

5.01–1

≠ 6800(pF)

( )

2

– 11030

2

R2

R1

2

+ (1 / ωC)

2

G = 20 × LOG10 1 +

Simulation Results

Setting f = 10 kHz f = 1 kHz
14 dB 13.95 7.42
12 dB 11.98 6.96
10 dB 10 6.34

8 dB 8 5.5
6 dB 6 4.43
4 dB 4 3.13
2 dB 2 1.64

No. 6866-17/24

LC75421M

• Calculation example 2

Specification Set frequency: f = 10000 Hz

Gain during maximum boost: G

+ 11.9 dB

= 11.9 dB

Let us use R1 = 11.030 kΩ and R2 = 45.054 kΩ.
The above constants are inserted in the following formula.

R2

R1

2

+ (1 / ωC)

2

C =

R2

)

2

– R1

2

1

2

πf

10

11.9/20

– 1

(

=

1

2

π10000

45054

3.94–1

≠ 1500(pF)

( )

2

– 11030

2

G = 20 × LOG10 1 +

Setting f = 10 kHz f = 1 kHz

11.9 dB 11.92 0.00

10.2 dB 10.64 0.00

8.5 dB 9.17 0.00

6.8 dB 7.52 0.00

5.1 dB 5.74 0.00

3.4 dB 3.88 0.00

1.7 dB 1.96 0.00

Simulation Results

No. 6866-18/24

LC75421M

Bass Shelving Circuit

The equivalent circuit and calculation formula during boost are shown below.

• Bass band equivalent circuit diagram

• Calculation example 1
Specification Mean frequency: f0 = 40 Hz

Gain during maximum boost: G

+ 14 dB

= 14 dB

Let us use R1 = 0 kΩ, R2 = 45.054 kΩ, C1 = 2.2 µF, and C1 >> C2.

We obtain R3 from G = 14 dB.

We obtain C2 from mean frequency f0 = 40 Hz.

R1 R2

R3

C1 C2

G

+14 dB

= 20 × LOG

10

R2 + R3

R3

R3 =

R2

10

G/20

–1

45054

5.01 – 1

= ≠ 11 KΩ

f 0 =

R3R2C1C2

1

2π

C2 = =

1

(2

πf0)

2

R2R3C1

1

(2

π × 40)

2

× 45054 × 11000 × (2.2 × 10–6)

≠ 0.015 µF

Simulation Results

Setting f = 100 Hz f = 1 kHz
14 dB 13.55 3.65
12 dB 11.73 3.51
10 dB 9.8 3.31

8 dB 7.89 3
6 dB 5.94 2.55
4 dB 3.97 1.92
2 dB 1.99 1.07

No. 6866-19/24

LC75421M

• Calculation example 2
Specification Mean frequency: f0 = 40 Hz

Gain during maximum boost: G = 12 dB
Let us use R1 = 0 kΩ, R2 = 45.054 kΩ, C1 = 2.2 uF, and C1 >> C2.

We obtain R3 from G = 12 dB.

We obtain C2 from mean frequency f0 = 40 Hz.

G

+12 dB

= 20 × LOG

10

R2 + R3

R3

R3 =

R2

10

G/20

–1

45054

3.98 – 1

= ≠ 15 KΩ

f 0 =

R3R2C1C2

1

2π

C2 = =

1

(2

πf0)

2

R2R3C1

1

(2

π × 40)

2

× 45054 × 15000 × (2.2 × 10–6)

≠ 0.01 µF

Setting f = 100 Hz f = 1 kHz
14 dB 11.73 4.27
12 dB 10.29 4.07
10 dB 8.74 3.78

8 dB 7.11 3.38
6 dB 5.41 2.82
4 dB 3.65 2.09
2 dB 1.85 1.15

Simulation Results

No. 6866-20/24

LC75421M

(4) Bass Peaking Circuit

The equivalent circuit and the formula for calculating the external RC with a mean frequency of 100 Hz are shown
below.

• Bass band equivalent circuit diagram

• Calculation example
Specification Mean frequency: f0 = 100 Hz

Gain during maximum boost: G = 11.9 dB
Let us use R1 = 0, R2 = 45.084 kΩ, and C1 = C2 = C.

We obtain R3 from G = 11.9 dB.

We obtain C from mean frequency f0 = 100 Hz.

We obtain Q.

C1 C2

R1 R2

R3

G

+11.9 dB

= 20 × LOG10 1 +

R2

2R3

R3 =

R2

2 10

11.9dB/20

–1

45084

2

× (3.936 – 1)

= ≠ 7.68 KΩ

f 0 =

R3R2C1C2

1

2π

C = =

1

2

πf0 R3R2

1

2π × 100 45084 × 7680

≠ 0.082 µF

Q =

R3R2

R3R2

2R3

1

•

≠ 1.66

Simulation Results

Setting f = 100 Hz f = 1 kHz

11.9 dB 11.88 0.00

10.2 dB 10.38 0.00

8.5 dB 8.79 0.00

6.8 dB 7.14 0.00

5.1 dB 5.42 0.00

3.4 dB 3.66 0.00

1.7 dB 1.85 0.00

No. 6866-21/24

LC75421M

Usage Cautions

(1) Upon power application, the internal analog switch status is undefined. Use an external countermeasure such as

muting until data is set.

(2) When performing initial data setting after applying power, send the initial data once, and then send the initial setting

data.

(3) To ensure that the digital frequency signal sent to the CL, DI, and CE pins do not spill over to the analog signal

block, either guard these signal lines with a ground pattern, or perform transmission using shielded wires.

No. 6866-22/24

LC75421M

Main volume control block

Input gain block

Fader block

Graphic equalizer block

Main volume control block

Main volume control block

Input gain block

Input gain block

Fader block

Fader block

THD

METER

Graphic equalizer block

Graphic equalizer block

Main volume control block

Input gain block

Fader block

Graphic equalizer block

Main Volume Control Step Characteristics Input Gain Step Characteristics

THD — Frequency CharacteristicsFader Step Characteristics

Attenuation — dB

Step setting — dB

Output level — dB

Step setting — dB

Attenuation — dB

Step setting — dB

Total harmonic distortion, THD — %

Frequency, f — Hz

No. 6866-23/24

LC75421M

Main volume control block

Input gain block

Fader block

THD

METER

Graphic equalizer block

Main volume control block

Input gain block

Fader block

THD

METER

Graphic equalizer block

THD — Input Level Characteristics

Total harmonic distortion, THD — %

Input level, VIN — dBV

Bass Control Characteristics Treble Control Characteristics

Super Bass Characteristics

Level — dBLevel — dB

Frequency, f — Hz

Level — dB

Frequency, f — Hz

Frequency, f — Hz

THD — Supply Voltage Characteristics

Total harmonic distortion, THD — %

Supply voltage — V

PS No. 6866-24/24

LC75421M

This catalog provides information as of September, 2003. Specifications and information herein are
subject to change without notice.

Specifications of any and all SANYO products described or contained herein stipulate the performance,
characteristics, and functions of the described products in the independent state, and are not guarantees
of the performance, characteristics, and functions of the described products as mounted in the customer’s
products or equipment. To verify symptoms and states that cannot be evaluated in an independent device,
the customer should always evaluate and test devices mounted in the customer’s products or equipment.

SANYO Electric Co., Ltd. strives to supply high-quality high-reliability products. However, any and all
semiconductor products fail with some probability. It is possible that these probabilistic failures could
give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire,
or that could cause damage to other property. When designing equipment, adopt safety measures so
that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective
circuits and error prevention circuits for safe design, redundant design, and structural design.

In the event that any or all SANYO products (including technical data, services) described or contained
herein are controlled under any of applicable local export control laws and regulations, such products must
not be exported without obtaining the export license from the authorities concerned in accordance with the
above law.

No part of this publication may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying and recording, or any information storage or retrieval system,
or otherwise, without the prior written permission of SANYO Electric Co., Ltd.

Any and all information described or contained herein are subject to change without notice due to
product/technology improvement, etc. When designing equipment, refer to the “Delivery Specification”
for the SANYO product that you intend to use.

Information (including circuit diagrams and circuit parameters) herein is for example only; it is not
guaranteed for volume production. SANYO believes information herein is accurate and reliable, but
no guarantees are made or implied regarding its use or any infringements of intellectual property rights
or other rights of third parties.