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Communication ICs
PCM codec IC for digital cellular
telephones
BU8731KV
The BU8731KV is a PCM codec IC developed for use with digital cellular telephones. It contains analog input / output
features such as a 14-bit linear precision, µ/ A-LA W codec, mic and speaker amplifiers, and switching transistor for the
ringer drive. This all makes the BU8731KV perfect for PDC and CDMA-type cellular telephones.
Applications
Digital cellular telephones
Features
1) 3V single power supply (VDD = 2.7V to 3.3V).
2) Built-in 14-bit precision linear, µ/ A-LAW codec.
3) Transmission filter for the codec unit conforms to
ITU-T recommendations.
4) Built-in PLL circuit for system clock generation.
5) Clock frequency for PCM data transmission can be
set anywhere between 64kHz (128kHz when linear)
to 2048kHz.
6) Analog input / output functions:
Built-in mic amplifier.
Built-in receiver speaker amplifier (32Ω BTL type).
Built-in earphone speaker amplifier (32Ω single
type).
Built-in drive amplifier for reception REXT (600Ω).
Built-in electronic volume control for gain adjust-
ment (for reception, transmission, and tone).
Data signal I / O circuit allows for connection to ex-
ternal devices.
For the REXT output and earphone output, soft-
mute function reduces pop noise when the power
is turned on and off.
7) DTMF signal and scale tone signal generator func-
tions are built into the tone signal generator block.
8) Internal switching transistor for ringer drive.
9) VQFP 48-pin package.
Absolute maximum ratings (Ta = 25C)
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Communication ICs BU8731KV
Recommended operating conditions (Ta = 25C)
Block diagram
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Communication ICs BU8731KV
Pin descriptions
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Communication ICs BU8731KV
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Communication ICs BU8731KV
Electrical characteristics (unless otherwise noted, Ta = 25C, DVDD = RXVDD = TXVDD = 3.0V, FSYNC = 8kHz)
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Communication ICs BU8731KV
Electrical characteristics (unless otherwise noted, Ta = 25C, DVDD = RXVDD = TXVDD = 3.0V, FSYNC = 8kHz,
FElectrical characteristics (gain of each attenuator = 0dB)
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Communication ICs BU8731KV
617
Communication ICs BU8731KV
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Communication ICs BU8731KV
Digital AC characteristics
619
Communication ICs BU8731KV
Measurement circuit
620
Communication ICs BU8731KV
External dimensions (Units: mm)
Appendix
Appendix1-Rev1.0
The products listed in this document are designed to be used with ordinary electronic equipment or devices
(such as audio visual equipment, office-automation equipment, communications devices, electrical
appliances and electronic toys).
Should you intend to use these products with equipment or devices which require an extremely high level of
reliability and the malfunction of with would directly endanger human life (such as medical instruments,
transportation equipment, aerospace machinery, nuclear-reactor controllers, fuel controllers and other
safety devices), please be sure to consult with our sales representative in advance.
Notes
No technical content pages of this document may be reproduced in any form or transmitted by any
means without prior permission of ROHM CO.,LTD.
The contents described herein are subject to change without notice. The specifications for the
product described in this document are for reference only. Upon actual use, therefore, please request
that specifications to be separately delivered.
Application circuit diagrams and circuit constants contained herein are shown as examples of standard
use and operation. Please pay careful attention to the peripheral conditions when designing circuits
and deciding upon circuit constants in the set.
Any data, including, but not limited to application circuit diagrams information, described herein
are intended only as illustrations of such devices and not as the specifications for such devices. ROHM
CO.,LTD. disclaims any warranty that any use of such devices shall be free from infringement of any
third party's intellectual property rights or other proprietary rights, and further, assumes no liability of
whatsoever nature in the event of any such infringement, or arising from or connected with or related
to the use of such devices.
Upon the sale of any such devices, other than for buyer's right to use such devices itself, resell or
otherwise dispose of the same, no express or implied right or license to practice or commercially
exploit any intellectual property rights or other proprietary rights owned or controlled by
ROHM CO., LTD. is granted to any such buyer.
Products listed in this document use silicon as a basic material.
Products listed in this document are no antiradiation design.
About Export Control Order in Japan
Products described herein are the objects of controlled goods in Annex 1 (Item 16) of Export Trade Control
Order in Japan.
In case of export from Japan, please confirm if it applies to "objective" criteria or an "informed" (by MITI clause)
on the basis of "catch all controls for Non-Proliferation of Weapons of Mass Destruction.
