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LGE Internal Use Only
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
3.4 Power Block
3.4.1 General
MSM7227, included RF, is fully covered by PM7540(Qualcomm PMIC). PM7540 cover the
power of MSM7227, MSM memory, RF block, Bluetooth, USIM and TCXO.
Major power components are :
PM7540(U400) : Phone main pmic
BD6083GUL(Sub-pcb, U101) : LCD Backlight charge pump, Cam LDO, Touch LDO
NUS5530(U403) : main power path switch( battery charging circuit)
MAX14528(U404) : OVP( Over voltage protection) IC
3.4.2 PM7540
The PM7540 device (Figure) integrates all wireless handset power management. The power management
portion accepts power from all the most common sources – battery, external charger, adapter, coin cell
back-up – and generates all the regulated voltages needed to power the appropriate handset electronics.
It monitors and controls the power sources, detecting which sources are applied, verifying that they are
within acceptable operational limits, and coordinates battery and coin cell recharging while maintaining
The handset electronics supply voltages. Eight programmable output voltages are generated using
low dropout voltage regulators, all derived from a common trimmed voltage reference.
A dedicated controller manages the TCXO warm-up and signal buffering, and key parameters (under-
voltage lockout and crystal oscillator signal presence) are monitored to protect against detrimental
conditions.
MSM device controls and statuses the PM7540 IC using Single Serial Bus Interface (SSBI) supplemented by
an Interrupt Manager for time-critical information. Another dedicated IC Interface circuit monitors multiple
trigger events and controls the power-on sequence.
3. Technical Brief
Содержание GD88O
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