Product Info

Smart LTE Module Series
SC66 Hardware Design
SC66_Hardware_Design 83 / 118
 The module offers three audio input channels, including one differential input pair and two
single-ended channels. The three sets of MICs are integrated with internal bias voltage.
 The output voltage range of MIC_BIAS is programmable between 1.6V and 2.9V, and the maximum
output current is 3mA.
 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 maximum output power is 1.5W when load is 8Ω.
 The headphone interface features stereo left and right channel output, and headphone insertion
detection function is supported.
3.22.1. Reference Circuit Design for Microphone Interfaces
MIC1_P
ECM-MIC
R2
R1
Module
D1
MIC1_N
33pF
C1
0R
0R
R3
0R
33pF
Figure 28: Reference Circuit Design for Analog ECM-type Microphone
SPK_N
54
AO
Speaker negative output
HPH_R
51
AO
Headphone right channel output
HPH_REF
50
AI
Headphone reference ground
HPH_L
49
AO
Headphone left channel output
HS_DET
48
AI
Headset insertion detection
High level by default.