Quectel SC20 Series - Reference Circuit Design for Microphone Interface

Smart Module Series
SC20_Series_Hardware_Design 65 / 133
 The module offers two audio input channels which are both single-ended channels.
 The earpiece interface uses differential output.
 The loudspeaker interface uses differential output as well. The output channel is available with a
Class-D amplifier whose output power is 879 mW when VBAT is 4.2 V and load is 8 Ω.
 The headphone interface features stereo left and right channel output, and supports headphone
insertion detect.
3.22.1. Reference Circuit Design for Microphone Interface
Figure 26: Reference Circuit Design for Microphone Interface
SPKP 10 AO Speaker output (+)
SPKN 11 AO Speaker output (-)
HPH_R 136 AO Headphone right channel output
HPH_GND 137 AI Headphone reference ground
HPH_L 138 AO Headphone left channel output
HS_DET 139 AI Headset hot-plug detect High level by default.