Huawei P20 - Page 10

EML-L29V100R001 Advanced Maintenance Manual V2.1
INTERNAL
2019-6-25
Huawei Confidential
Page 10 of 67
Subsystem
Module
Unit
Function
prototype and is also used for device
commissioning and testing during the R&D
process.
SIM card ports
Power supply,
protective circuit,
and SIM card tray
Includes the SIM card tray and related
connection circuits.
Color LCD and
backlight
LCD drive,
connection method,
and backlight
control
Both the phone screen and the LCD backlight
brightness are controlled using the CABC and
LABC functions.
Speaker
Drive method,
connection method,
and speaker
components
The power of the speaker that plays polyphonic
ringtones for incoming calls can be 500 mW.
This unit features good frequency responses to
play 20 Hz to 20 kHz audio files and can also
be used as a mono speaker to play MP3 files.
Receiver
Drive method,
connection method,
and receiver-related
components
The power of the receiver for calls must be less
than 30 mW.
Microphone
Port circuit,
connection method,
and
microphone-related
components
The phone features dual built-in silicon
microphones with noise reduction.
Earphone
Headset, headset
jack circuit, and
microphone port
circuit
The phone provides a headset jack for call
output or MP3 output. The microphone is
located on the headset line to transmit the
sound to the phone.
Vibrator port
Drive method,
connection method,
and vibrator
This unit vibrates when a call is received.
Accelerometer
I2C port control
The accelerometer is an auxiliary module of the
game engine.
Gyroscope
I2C port control
3-axis angular rate sensor
Compass
I2C port control
Geomagnetic sensor
Fingerprint
sensor
SPI port control
Identifies fingerprints.
Proximity
sensor
I2C port control
Senses ambient light and proximity light.
Hall sensor
GPIO control
Senses protective cases.
Power
distribution
network and
Power distribution
network
This unit includes filtering networks and cables
for the power supply.
Backup battery
PMIC charges the capacitor for maintaining the