Datasheet

INTERFACE SEQUENCE
Power-On, Attach, and Play Back Sequence
D+(pin4),
D (pin3)-
0V
BusIdle
V (pin2)
BUS
SSPND (pin29)
V L (pin18),
V R(pin22)
OUT
OUT
BusReset SetConfiguration
1st AudioData 2nd AudioData
5.0V(typ)
2.5V(typ)
SOF SOF SOF
1ms
DeviceSetup
ReadyforSetup ReadyforPlayback
InternalReset
700 sm
PCM2912A
www.ti.com .......................................................................................................................................................................................... SLES230 – SEPTEMBER 2008
The PCM2912A is ready for setup when the reset sequence has finished and the USB bus is attached. After a
connection has been established, the PCM2912A is ready to accept USB audio data. While waiting for the audio
data (that is, in an idle state), the analog output is set to bipolar zero (BPZ).
When receiving the audio data, the PCM2912A stores the first audio packet, which contains 1-ms audio data,
into the internal storage buffer. The PCM2912A starts playing the audio data when the subsequent Start of
Frame (SOF) packet is detected, as shown in Figure 33 .
Figure 33. Initial Sequence
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Product Folder Link(s): PCM2912A