LG L601i Service Manual page 44

3. TECHNICAL BRIEF
3.10.3. Power Block
3.10.3.1. General
MSM6250A, included RF, is fully covered by PM6650-2(Qualcomm PMIC). PM6650-2 cover the power
of MSM6250A, MSM memory, RF block, Bluetooth, Trans flash, USIM and TCXO. Major power
components are :
PM6650-2(U403) : Phone power supply
QST4(Q400) : External charger supply switching
SI3493DV(Q401) : Main Battery charging control
BH28FB1WHFV(U401) : LCD Power supply
ISL9011IRGCZ(U400) : Camera power supply
AAT2805IXN-4.5-T1(U500) : Backlight & Flash LED Power supply
3.10.3.2. PM6650-2
The PM6650-2 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 PM6650-2 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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