User Manual

Bluetooth Audio Module

Ehong Technology Co., Ltd

The module has an internal USB pull-up resistor. This pulls the USB_DP pin weakly high when

module is ready to enumerate. It signals to the USB master that it is a full speed (12Mbit/s) USB

device.

Figure 15: USB Connections

Identifier

Value

Function

27Ω Nominal

Impedance matching to USB

cable

Table 14: USB Interface Component Values

Note:

USB_ON is only used when the firmware need an input to detect if USB is connected and the USB

function shall be enabled. In such case it is shared with the module PIO terminals. If detection is not

needed (firmware already runs with USB, such as USB DFU or USB CDC), USB_ON is not needed.