Product Info

Smart Module Series
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3.9. USB Interface
SC20 series contains one integrated Universal Serial Bus (USB) interface which complies with the USB
2.0 specification and supports high-speed (480 Mbps) and full-speed (12 Mbps) modes. The USB
interface is used for AT command communication, data transmission, software debugging and firmware
upgrade.
The following table shows the pin definition of USB interface.
Table 11: Pin Definition of USB Interface
USB_VBUS can be powered by the USB power or adapter. It can be used for USB connection detection,
as well as for battery charging via the internal PMU. The input voltage of power supply ranges from 4.35 V
to 6.3 V, and the typical value is 5.0 V. SC20 series supports charging management for a single Li-ion
battery, but different charging parameters should be set for batteries with different models or capacities.
The module is available with a built-in linear-charging circuit which supports maximally 1.44 A charging
current.
Pin Name Pin No. I/O Description Comment
USB_VBUS 141, 142 PI
USB 5 V power input and USB
insertion detection
Vmax = 6.3 V
Vmin = 4.35 V
Vnom = 5.0 V
USB_DM 13 AIO USB 2.0 differential data (-)
Compliant with USB 2.0
standard.
Require differential
impedance of 90 Ω.
USB_DP 14 AIO USB 2.0 differential data (+)
USB_ID 16 AI USB ID detect High level by default.