Product Info

VTech proprietary and confidential
VTech Communications LTD.
R&D Department
The document is VTech’s proprietary information, Please do not disclose to third party without VTech’s consent
Ref. No.: 20191009 Version: 01 Date: 09 Oct, 2019 Page 13 of 33
represents the left channel and channel 1 or channel B represents the right channel.
7.2.1 Audio codec block diagram
Figure 7-2 Audio codec input and output stages
The VTBM-A01 BT Module audio codec uses a fully differential architecture in the analog signal path. This
architecture results in low common-mode-noise sensitivity and good power supply rejection while effectively
doubling the signal amplitude. It operates from a dual power supply, VDD_AUDIO for the audio circuits and
VDD_AUDIO_DRV for the audio driver circuits.
7.2.2 ADC
The VTBM-A01 BT Module consists of two high-quality ADCs:
• Each ADC has a second-order Sigma-Delta converter.
• Each ADC is a separate channel with identical functionality.
• Each channel has an analog and a digital gain stage.
7.2.2.1 ADC sample rate selection
Each ADC supports the following predefined sample rates:
• 8 kHz
• 11.025 kHz