Power Block - LG U8500 Service Manual

3. TECHNICAL BRIEF

3.10.3 Power Block

3.10.3.1 General
MSM6250, included RF, is fully covered by PM6650(Qualcomm PMIC). PM6650 cover the power of
MSM6250, MSM memory, RF block, Bluetooth, Trans flash, USIM and TCXO.
Major power components are :
PM6650(U402) : Phone power supply
BH28FB1WHFV(U411) : LCD Power supply
QST4(Q403,Q404) : External charger supply switching
SI3493DV (Q402) : Main Battery charging control
SI8402DB,SI8407DB(Q400,Q401) : WCDMA PAM power selection control
MIC2211(U501) : Camera power supply
3.10.3.2 PM6650
The PM6650 device 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 PM6650 IC using a three-line Serial Bus Interface (SBI)
supplemented by an Interrupt Manager for time-critical information. Another dedicated IC Interface
circuit monitors multiple trigger events and controls the power-on sequence.
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