Pcm And I2C Interfaces - Quectel EP06 Manual

 It is important to route the USB 2.0&3.0 signal traces as differential pairs with total grounding.
For USB 2.0 routing traces, the trace impedance of a differential pair should be 90Ω, and the
1)
length matching of the differential pair should be less than 2mm.
For USB 3.0 routing traces, the trace impedance of Tx and Rx differential pairs should be 90Ω,
2)
and the length matching of Tx and Rx differential pairs should be less than 0.7mm.
 Do not route signal traces under crystals, oscillators, magnetic devices or RF signal traces. It is
important to route the USB 2.0&3.0 differential traces in inner-layer with ground shielding on not only
upper and lower layers but also right and left sides.
 If USB connector is used, please keep the ESD protection components to the USB connector as
close as possible. Pay attention to the influence of junction capacitance of ESD protection
components on USB 2.0&3.0 data lines. The capacitance value of ESD protection components
should be less than 2.0pF for USB 2.0, and less than 0.4pF for USB 3.0.
 If possible, reserve a 0R resistor on USB_D+ and USB_D- lines.
NOTE
S
"*" means under development.

3.6. PCM and I2C Interfaces

The following table shows the pin definition of PCM and I2C interfaces that can be applied in audio codec
design.
Table 8: Pin Definition of PCM and I2C Interfaces
Pin No. Pin Name
45 PCM_CLK
47 PCM_DOUT
49 PCM_DIN
51 PCM_SYNC
30 I2C_SCL
32 I2C_SDA
Power
I/O Description
Domain
IO 1.8V PCM clock signal
DO 1.8V PCM data output
DI 1.8V PCM data input
IO 1.8V PCM frame synchronization
DO 1.8V I2C serial clock
IO 1.8V I2C serial data
Comment
Require external pull-up to
1.8V.
Require external pull-up to
1.8V.
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