Data Sheet

IDC7 Bluetooth Module
Model: IDC747
Page: 14 Copyright IOT747 Ref: IDC747-DTS-V003
IOT747, 122 Ross Street, Cambridge, CB1 3BU, United Kingdom
Check www.iot747.com for updates. Email: [e-mail] Back to TOC
IDC747 Module
Product Information Data Sheet
Ref: IDC747-DTS-V003
Latest Update: July 20, 2021
122 Ross Street, CB13BU
Cambridge, United Kingdom
www.iot747.com
An example amplifier circuit suitable for connecting external headphones.
When connecting to external devices such as laptops in a “Line In” configuration there is a
possibility that the sleeve of the audio cable can carry noise derived from the laptop. Also
external devices connected through the audio cable sleeve can have different ground
potentials which causes currents to flow through the sleeve ground. In this case it is
important to isolate the sleeve ground from the audio amplifier to avoid the noise coupling to
the amplifier and degrading the signal source. In this case add a filter circuit or ferrite bead
connecting the sleeve ground to the ground on the application board as shown below.