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USB_VBUS
USB_DM
USB_DP
Module
Figure 12: USB Interface Reference Design (OTG Not Supported)
VBAT
C1
10 μF
VBAT
GPIO
USB_VBUS
USB_DM
USB_DP
USB_ID
Module
Figure 13: USB Interface Reference Design (OTG Supported)
In order to ensure USB performance, comply with the following principles when designing the USB
interface.
⚫
Route the USB signal traces as a differential pair with total grounding. The impedance of USB
differential trace should be controlled to 90 Ω.
⚫
Keep the ESD protection devices as close as possible to the USB connector. Pay attention to the
influence of junction capacitance of ESD protection devices on USB data lines. Typically, the
capacitance value should be less than 2 pF.
⚫
Do not route signal traces under crystals, oscillators, magnetic devices or RF signal traces. Route the
USB differential traces in inner-layer of the PCB, and surround the traces with ground on that layer
SC262R_Series_Hardware_Design
C1
100 nF
GND
L1
4
SW
1.0 μH
5
VIN
1
EN
R1
10K
U1
C3
100 nF
GND
D1
D2
D3
ESD ESD ESD
7
VOUT
8
VOUT
C2
6
NC
22 μF/
10 V
D3
D4
D1
D2
ESD
ESD
ESD
ESD
Smart Module Series
1
VUSB
2
USB_DM
3
USB_DP
4
USB_ID
5
GND
1
VUSB
2
USB_DM
3
USB_DP
4
USB_ID
5
GND
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