User's Manual

MeiG hardware design guide
21
Figure 4.25: Recommended Circuit with External Audio Power Amplifier
4.9.5 I2S Interface
There is a set of GPIO-compatible I2S interfaces inside the module. The pins used by this function are
as follows:
Name
Pin
Input/Output
Description
GPIO3
89
I
I2S1 input DATA
GPIO2
90
O
I2S1 output DATA
GPIO1
91
O
I2S1_ SCK
GPIO0
92
O
I2S1_ WS
4.10 USB Interface
The SLM756P supports a USB 2.0 High speed interface. It must control the 90 ohm differential
impedance during Layout and control the external trace length according to the internal trace length of
the module.The module supports OTG function at the same time (requires external circuit to provide
external 5V power supply).The voltage input range during charging is as follows:
Table 4.9: Voltage input range during charging
Name
Description
Minimum
Typical
Maximum
Unit
VBUS
Input range
4
-
6.3
V
The USB plug-in detection of the module is realized by the VBUS and DP/DM data lines. When the
USB cable is inserted, the VBUS voltage is detected first, and then the DM/DP pull-up state is detected
to determine whether the USB data line or the charger is inserted. Therefore, if you need to use the
USB function, please be sure to connect VBUS to the 5V power supply on the data line.
USB is a high-speed mode. It is recommended to connect a common-mode inductor to the side of the
USB connector to effectively suppress EMI interference. At the same time, the USB interface is an
external interface. It is recommended to add a TVS tube to prevent static damage caused by plugging
and unplugging the data cable. When selecting TVS, please pay attention to the load capacitance
should be less than 1pf. VBUS also needs to increase the TVS tube. If there is anti-surge demand, it is
also necessary to increase the anti-surge tube. The connection diagram is as follows: