Datasheet

D+/D–
2.5V(Typ)
0V
InternalReset
ReadyforSetup
SOF
ReadyforPlayback
BusReset
SetConfiguration
SOF SOF
BPZ
BusIdle
5V (Typ)
1 AudioData
st
2 AudioData
nd
V (Pin3)
BUS
SSPND
V L
OUT
V R
OUT
700 sm
DeviceSetup
1ms
T0055-02
D+/D–
V L
OUT
V R
OUT
AudioDataAudioData Last AudioData
Detach
SOF SOF SOF SOF SOF
1ms
V (Pin3)
BUS
T0056-02
PCM2906C
SBFS037 –NOVEMBER 2011 www.ti.com
INTERFACE SEQUENCE
Power-On, Attach, and Playback Sequence
The PCM2906C is ready for setup when the reset sequence has finished and the USB device is attached. After a
connection has been established by setup, the PCM2906C is ready to accept USB audio data. While waiting for
the audio data (idle state), the analog output is set to bipolar zero (BPZ).
When receiving the audio data, the PCM2906C stores the first audio packet, which contains 1-ms audio data,
into the internal storage buffer. The PCM2906C starts playing the audio data when detecting the next
start-of-frame (SOF) packet, as illustrated in Figure 32.
Figure 32. Initial Sequence
Play, Stop, and Detach Sequence
When the host finishes or aborts the playback, the PCM2906C stops playing after the last audio data have
played, as shown in Figure 33.
Figure 33. Play, Stop, and Detach Sequence
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Product Folder Link(s): PCM2906C