Sanyo LA7471M Specifications

Ordering number : EN4488A

O3098HA (OT)/40596TH/42094TH (OT) B-0326 No. 4488-1/10

LA7471M

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

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

Two-Channel Microphone Amplifier

for Video Camera

Monolithic Linear 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.

Overview

The LA7471M is a stereo microphone amplifier for use in
video camera products. It includes an automatic wind
noise detection and removal circuit, an equalization circuit
to compensate for microphone frequency characteristics
and an L/R mixing circuit to provide a good stereo image.
The LA7471M provides high quality audio for video
camera applications.

Functions

• Microphone amplifier (two channels)

• Internal/external microphone switching

• Automatic wind noise detection/prevention circuit

• High-pass filter and disable switch

• Internal microphone power supply

• External microphone power supply (with current
limiter)

• Ripple filter

• Stereo/mono detection for external microphones

Features

• Automatic wind noise detection and exclusion circuit
(The high-pass filter provides a first-order to third-order
linear conversion.)

• High-quality audio (low noise, microphone frequency
characteristic compensation, and stereo enhancement)

Package Dimensions

unit: mm

3162B-QFP36

Specifications

Maximum Ratings at Ta = 25°C

Operating Conditions at Ta = 25°C

Parameter Symbol Conditions Ratings Unit

Maximum supply voltage V

CC

max 7.0 V
Allowable power dissipation Pd max Ta ≤ 65°C 300 mW
Operating temperature Topr –10 to +65 °C
Storage temperature Tstg –55 to +150 °C

Parameter Symbol Conditions Ratings Unit

Recommended supply voltage V

CC

5.0 V

Operating supply voltage range V

CC

op 4.5 to 5.5 V

SANYO: QFP36

[LA7471M]

Operating Characteristics at Ta = 25°C, VCC= 5.0 V, f = 1.0 kHz, RL= 10 kΩ

Block Diagram

No. 4488-2/10

LA7471M

Parameter Symbol Conditions

Ratings

Unit

min typ max

Current dissipation

I

CC1

INT MIC in, EXT VCCoff, L/Rch 5.5 8 10.5 mA

I

CC2

INT MIC in, EXT VCCon, L/Rch 6 9 12 mA

VG

1

EXT MIC in, L/Rch 27.3 27.8 28.3 dB

Voltage gain

VG

2

INT MIC in, Gain CTL Hi, L/Rch 23.8 24.3 24.8 dB

VG

3

INT MIC in, Gain CTL Mi, L/Rch 20.8 21.3 21.8 dB

VG

4

INT MIC in, Gain CTL Lo, L/Rch 17.8 18.3 18.8 dB

Total harmonic distortion THD

INT MIC in, EXT MIC in

0.05 0.2 %

V

O

= 300 mVrms, L/Rch

Maximum output V

OM

INT MIC in, EXT MIC in

1.0 1.4 Vrms

THD = 1%, L/Rch

V

NO1

EXT MIC in, L/Rch, Rg = 1 kΩ, JIS-A 22 32 µVrms

Output noise voltage

V

NO2

INT MIC in, L/Rch, Rg = 1 kΩ, JIS-A

16 24 µVrms

Gain CTL Hi, Mi, Lo

Input switch crosstalk SW

CR

INT MIC in → EXT MIC in (Rg = 1 kΩ)

80 70 dB

f = 10 kHz, L/Rch

Inter-channel crosstalk CH

CR

INT/EXT MIC, Lch → Rch, Rch → Lch,

51 45 dB

f = 10 kHz

Internal microphone power supply

V

INM

When pin 31 is DC, with 30 kΩ load 2.65 2.8 2.95 V

output voltage
External power supply output voltage V

EXM

When connected to pin 16 (output current) 4.0 4.5 V

External power supply limiter current I

LIM

When connected to pin 16 (output current) 30 mA

Input switching control voltage

CTL

H

High level, pin 29/pin 35 DC 1.3 V

CC

V

CTL

L

Low level, pin 29/pin 35 DC 0 0.7 V

Input impedance Z

IN

INT/EXT MIC in, L/Rch 60 75 90 kΩ

Output impedance Z

O

Pins 8 and 20 1 5 Ω

Unit (resistance: Ω)

Test Circuit Diagram

No. 4488-3/10

LA7471M

Unit (resistance: Ω, capacitance: F)

Sample Application Circuit

No. 4488-4/10

LA7471M

Unit (resistance: Ω, capacitance: F)

Switch Operation Table

No. 4488-5/10

LA7471M

Item Symbol SW1 SW2 SW3 SW4 SW5 SW6 V15 V29 V35 Test point

Current dissipation 1 I

CC1

BBBBCALHLA

1

Current dissipation 2 I

CC2

BBBBCBLHLA

1

Voltage gain 1

VG

1-1

ABBBCALLLV

O1

VG

1-2

BBABCALLLV

O2

Voltage gain 2

VG

2-1

BABBCAHHLV

O1

VG

2-2

BBBACAHHLV

O2

Voltage gain 3

VG

3-1

BABBCAMHLV

O1

VG

3-2

BBBACAMHLV

O2

Voltage gain 4

VG

4-1

BABBCALHLV

O1

VG

4-2

BBBACALHLV

O2

THD

1-1

ABBBCALLLV

O1

THD

1-2

BBABCALLLV

O2

THD

2-1

BABBCAHHLV

O1

Total harmonic distortion

THD

2-2

BBBACAHHLV

O2

THD

3-1

BABBCAMHLV

O1

THD

3-2

BBBACAMHLV

O2

THD

4-1

BABBCALHLV

O1

THD

4-2

BBBACALHLV

O2

V

OM1-1

ABBBCALLLV

O1

V

OM1-2

BBABCALLLV

O2

V

OM2-1

BABBCAHHLV

O1

Maximum output

V

OM2-2

BBBACAHHLV

O2

V

OM3-1

BABBCAMHLV

O1

V

OM3-2

BBBACAMHLV

O2

V

OM4-1

BABBCALHLV

O1

V

OM4-2

BBBACALHLV

O2

Output noise voltage 1

V

NO1-1

BBBBCALLLV

O1

V

NO1-2

BBBBCALLLV

O2

V

NO2-1

BBBBCAHHLV

O1

V

NO2-2

BBBBCAHHLV

O2

Output noise voltage 2

V

NO2-3

BBBBCAMHLV

O1

V

NO2-4

BBBBCAMHLV

O2

V

NO2-5

BBBBCALHLV

O1

V

NO2-6

BBBBCALHLV

O2

Input switch crosstalk

S

CR1

BABBCALLLV

O1

S

CR2

BBBACALLLV

O2

C

cn1-1

ABBBCALLLV

O2

Inter-channel crosstalk

C

cn1-2

BBABCALLLV

O1

C

cn2-1

BABBCAHHLV

O2

C

cn2-2

BBBACAHHLV

O1

Internal microphone power

V

INM

BBBBCALLLV

31

supply output voltage
External power supply

V

EXM

BBBBBBLLLV

16

output voltage
External power supply

I

LIM

BBBBABLLLA

2

limiter current

Pin Functions

Unit (resistance: Ω)

No. 4488-6/10

LA7471M

Pin No. Function Internal Circuit DC Voltage Description

1

27

2

26

3

25

4

24

5

23

6

22

7

21

INT in

Gain CTL
AMP in

Gain CTL
AMP N out

Gain CTL
AMP out

Mix AMP
NFB

Mix AMP
out

HPF in

2.1 V

2.1 V

2.1 V

2.1 V

2.1 V

2.1 V

2.1 V

Internal microphone input
The input impedance is 75 kΩ.

Gain control amplifier input
The input impedance is 100 kΩ.

Gain control amplifier inverted output

Gain control amplifier output

Mixer amplifier NFB pin

Mixer amplifier output

High-pass filter amplifier input
This is a high impedance input.

Continued from preceding page.

Unit (resistance: Ω)

No. 4488-7/10

LA7471M

Pin No. Function Internal Circuit DC Voltage Description

8

20

9

10

11

12

13

14

15

HPF out

AMP NFB

AMP out

LPF in

LPF out

V

CC

EXT VCCpower

Gain CTL

2.1 V

2.1 V

2.1 V

2.1 V

2.1 V

V

CC

Output for the high-pass filter 5 dB amplifier and the
EXT mode 15 dB amplifier

NFB for the amplifier that adjusts the wind noise
exclusion high-pass filter on/off level

Output for the amplifier that adjusts the wind noise
exclusion high-pass filter on/off level
This is a low impedance output.

Buffer input for forming a low-pass filter.
The input impedance is 200 kΩ.

Buffer output for forming a low-pass filter.
This is a low impedance output.

Power supply for circuits other than the external
V

CC

circuit

External VCCcircuit power supply

Gain control pin

High level (4 V or higher): 6 dB
Mid level (2 to 3 V): 3 dB
Low level (1 V or lower): 0 dB

Continued on next page.

Continued from preceding page.

Unit (resistance: Ω)

No. 4488-8/10

LA7471M

Continued on next page.

Pin No. Function Internal Circuit DC Voltage Description

16

17

18

19

28
36

29

EXT V

CC

HPF DET

BIAS

EXT MIC mono

Mic AMP out

Input select
CTL2

2.1 V

2.1 V

External power supply with current limiter
Capable of providing at least 4 V when an output
current is 25 mA.
When the output voltage is 0 V, the output current is
less than 25 mA.

Detects the level used to turn the high-pass filter on
and off.

Reference voltage

Outputs a low level only when the external
microphone is monophonic.

Microphone amplifier output
This is a low-impedance output.

Internal/external switch
Control pin used to determine stereo or monophonic
operation

No. 4488-9/10

LA7471M

Continued from preceding page.

Unit (resistance: Ω)

Pin No. Function Internal Circuit DC Voltage Description

30
34

31

32

33

35

EXT in

Mic V

CC

Ripple filter

GND

Input select
CTL1

2.1 V

2.8 V

2.1 V

0

External microphone input
The input impedance is 75 kΩ.

Power supply for the internal microphone

This pin is used to exclude ripple from internal
circuits. Connect a capacitor and a resistor of 75 kΩ
externally to exclude ripple.

Internal/external switch
Control pin used to determine stereo or monophonic
operation

PS No. 4488-10/10

LA7471M

This catalog provides information as of December, 1998. 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.