○Product structure：Silicon monolithic integrated circuit ○This product has no designed protection against radioactive rays

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TSZ02201-0C2C0E100460-1-2

© 2015 ROHM Co., Ltd. All rights reserved.

TSZ22111・14・001

www.rohm.com

16.Dec.2015 Rev.001

BD37521FS

General Description

BD37521FS is a sound processor with built-in 2-band

equalizer for car audio. Other features are stereo 4ch input

selector, input-gain control, main volume, loudness, and a

4ch

fader volume. It is equipped with an “Advanced switch

circuit”, which is an original ROHM technology that

reduces various switching noise (ex. No-signal, low

frequency such as 20Hz & large signal inputs). Also, this

“Advanced switch” makes control of microcomputer easier

and can be used for designing high quality car audio

system.

Features



Reduced switching noise of input gain control, mute,

main volume, fader volume, bass, treble,

and

loudness by using advanced switch circuit.



Built-in 1 differential input selector and 3 single-ended

input selectors



Built-in ground isolation amplifier inputs which is ideal

for external stereo input.



Built-in input gain controller which reduces switching

noise for volume of a portable audio input.



Lesser number of external components due to built-in

2-band equalizer filter. This makes it possible to

control the Gv of 2-band equalizer and Gv of loudness



A gain adjustment quantity of ±20dB with a 1 dB step

gain adjustment is possible for the bass and treble.



Energy-saving

design

resulting

in

low

current

consumption is achieved by utilizing the BiCMOS

process. It has the advantage in quality over scaling

down the power heat control of the internal regulators.



Input pins and output pins are organized and

separately laid out to keep the signal flow in one

direction that consequently simplify pattern layout of

the set board and decrease the board dimensions.



Key Specifications



Power Supply Voltage Range:

7.0V to 9.5V



Circuit Current (No Signal):

38mA(Typ)



Total Harmonic Distortion:

0.001%(Typ)



Maximum Input Voltage:

2.3Vrms (Typ)



Cross-talk Between Selectors:

-100dB (Typ)



Volume Control Range:

+15dB to -79dB



Output Noise Voltage:

3.8µVrms(Typ)



Residual Output Noise Voltage:

1.8µVrms (Typ)



Operating Temperature Range:

-40°C to +85°C

Package

W(Typ) x D(Typ) x H(Max)

Applications

It is best suited for car audio applications. It is also suitable

for other audio equipment such as mini-component,

micro-component, television, etc.

SSOP-A24

10.00mm x 7.80mm x 2.10mm

Datasheet

Datasheet