Power Block - LG HB620 Service Manual

3. TECHNICAL BRIEF

3.8 Power Block

3.8.1 General
MSM6280, included RF, is fully covered by PM6650(Qualcomm PMIC). PM6650 cover the power of
MSM6280, MSM memory, RF block, Bluetooth, USIM and TCXO.
Major power components are :
PM6650 : Phone power supply
MAX8645Y : LCD Backlight/Flash charge pump
3.8.2 PM6650
As shown in [Fig. 3.16], 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(undervoltage lockout and crystal oscillator signal presence) are monitored to protect
against detrimental conditions. MSM device controls and statuses the PM6650 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.
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