Huawei U8185 Maintenance Manual page 35

U8185
Maintenance Manual
Table 9-1 Circuit diagram signal summary
Signal
VCHG
VPH_PWR
BAT_FET_N
VBAT
VCOIN
BATT_THERM
VREG_S1
VREG_S2
VREG_S3
VREG_S4
VREG_L1
VREG_L2
VREG_L3
VREG_L4
VREG_L5
VREG_L6
VREG_L7
VREG_L8
VREG_L9
VREG_L10
VREG_L11
VREG_L12
VREG_L13
Issue 1.0 (2012-03-23)
Description

Charging current input from a charger

Used for detecting the connection of a charger
Main power supply, supplying power to the main chip's
power unit
Control signal of the MOS (Q201)
Input end for battery voltage detection and output end
for trickle charging.

Backup power supply, NC

When sudden loss of power occurs, the backup
power supply (if any) will supply power to the
phone until the main battery power recovers, so that
the phone will not shut down.

Battery temperature detection.
 Detects the voltage of the thermistor inside the
battery to determine the battery's temperature.
Supplies power to the processor core.
Supplies power to the MSM application processor.
Supplies power to the memory and digital I/O.
Supplies power to the RF and analog section.
NC
Supplies power to the RF's front end.
Supplies power to the MIPI DSI circuit.
Supplies power to the digital PLL.
NC
Supplies power to the MSM's analog section.
TCXO power supply; controlled by internal TCXO.
Supplies power to the MIPI CSI circuit.
Supplies power to the eMMC module on the MSM.
Supplies power to the TCXO_OUT_D1 buffer, AMUX,
and XO ADC circuits.
Supplies power to the SD circuit.
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9 Principles and Failure Analysis
Reference Measurement
or Wave Form
Detection range: 0–18 V
Voltage range: 0–4.2 V
Battery voltage, range: 0–4.2
V
None.
Cd
1.1 V
1.1 V
1.8 V
2.35 V
2.85 V
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