LG -A290 Service Manual page 53

IS/EIAJ interface is designed to transmit high quality audio data. Figure 3.13.4 and Figure 3.13.5 illustrate the timing
diagram of the two types of interfaces. IS/EIAJ can support 3 kHz, 44.1 kHz, and 48 kHz sampling rate audio signals. The
clock frequency of IS/EIAJ can be 3×(sampling frequency), or 64×(sampling frequency). For example, to transmit a 44.1
kHz CD-quality music, the clock frequency should be 3 × 44.1 kHz = 1.411 MHz or 64 × 44.1 kHz = .84 MHz.
IS/EIAJ interface is not only used for Bluetooth module, but also for external DAC components. Audio data can easily
be sent to the external DAC through the IS/EIAJ interface. In this document, the IS/EIAJ interface is referred to as EDI
(External DAC Interface).
LGE Internal Use Only
Figure 3.13.3 Timing diagram of Bluetooth application
Figure 3.13.4 Block diagram of digital circuit of audio front end
Figure 3.13.5 Block diagram of digital circuit of audio front end
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