1 Introduction

Voice Activity Detector (VAD) is a voice-triggered system wake-up mechanism. VAD enables the rest of the system to be in sleep mode in the absence of voice activity, thereby consuming very low power. VAD-based systems generate an interrupt on detection of voice activity. Figure 1-1 shows how the VAD responds to voice activity.

Figure 1-1 VAD Example

VAD is supported on all analog-to-digital converter (ADC) channels of the TLV320ADCx120/PCMx120-Q1 device family, that is, on analog and digital microphone channels. The digital microphone channel is preferred for low-power applications. This application note describes the operation of the VAD, the tunable parameters, and the device configurations required to support VAD.