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)
SSPND
700 sm
Device Setup
1 ms
V (Pin 3)
BUS
V L
V R
OUT
OUT
First Audio Data
Second Audio Data
D+/D-
Audio DataAudio Data Last Audio Data
Detach
SOF SOF SOF SOF SOF
1 ms
V (Pin 3)
BUS
V L
V R
OUT
OUT
PCM2900C
PCM2902C
SBFS039 –SEPTEMBER 2011 www.ti.com
INTERFACE SEQUENCE
Power On, Attach, and Playback Sequence
The PCM2900C/2902C is ready for setup when the reset sequence has finished and the USB bus is attached.
After connection has been established by setup, the PCM2900C/2902C is ready to accept USB audio data.
While waiting, the audio data (idle state) and analog output are set to bipolar zero (BPZ).
When receiving the audio data, the PCM2900C/2902C stores the first audio packet, which contains 1-ms audio
data, into the internal storage buffer. The PCM2900C/2902C starts to play 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 playback, the PCM2900C/2902C 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): PCM2900C PCM2902C