ROHM BU8710AKS Datasheet

Communication ICs

4-channel ADPCM transcoder for
digital cordless telephone base stations

BU8710AKS

This is an ADPCM transcoder which conforms to the G.721 standards listed in the 1988 edition of the CCITT recommen­dations. Simultaneous processing of four encoder and decoder channels is possible, enabling superb affinity with the
quadruple TDMA which is a standard for PHS (personal handy phone) systems. In turn, this enables voice processing
units for individual base stations in the public telephone network to be configured on single chips.

Applications
PHS base stations

Features

1) Can be connected to µ-law and A-law PCM codec
through a serial interface. (Both long frames and
short frames can be accommodated.)

2) Various functions can be controlled through a CPU
interface.

3) An internal power save mode can be controlled sepa­rately for individual channels. (Separate encoder and
decoder control are possible.) In addition, external
pin control enables power consumption to be re­duced for the chip as a whole.

4) An internal muting function can be controlled sepa­rately for individual channels. (Separate encoder and
decoder control are possible.)

5) An internal function silence detection is provided,
which can be controlled separately for individual
channels. (Applicable only to encoders.)

6) An internal background noise generation function is
provided, which can be controlled separately for in­dividual channels. (Applicable only to decoders.)

7) The G.711 (µ-law or A-law) output level can be atte­nuated freely on individual channels.

8) An internal 64kbps data through mode is provided,
which can be controlled separately for individual
channels.

9) Internal 32kbps and 64kbps data loop back modes
are provided, which can be controlled separately
for individual channels.

10) An internal clock generator circuit is provided.

11) SQFP 80 pin package is used.

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Communication ICs BU8710AKS

Block diagram

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Communication ICs BU8710AKS

FAbsolute maximum ratings (Ta = 25_C)

FRecommended operating conditions (Ta = 25_C)

FPin descriptions

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Communication ICs BU8710AKS

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Communication ICs BU8710AKS

FElectrical characteristics
DC characteristics (unless otherwise noted, Ta = 25_C, VDD = 5.0V)

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Communication ICs BU8710AKS

AC characteristics (unless otherwise noted, Ta = 25_C, VDD = 5.0V)

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Communication ICs BU8710AKS

Input/output signal timing charts

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Communication ICs BU8710AKS

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Communication ICs BU8710AKS

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Communication ICs BU8710AKS

Note: In Figures 2 to 5, when the 64kbps data through mode is set, the normal 4-bit output encoder output is equivalent
to the timing of the decoder 8-bit output (corresponding to Figure 5), and the normal 4-bit input decoder input is equivalent
to the timing of the encoder 8-bit input (corresponding to Figure 2).

Correspondence between encoder and decoder input pins

Correspondence between encoder and decoder output pins

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