Power Block - LG KF310 Service Manual

3.8 Power Block

3.8.1 General
MSM6245, included RF, is fully covered by PM6658(Qualcomm PMIC). PM6658 cover the power of
MSM6245, MSM memory, RF block, Bluetooth, USIM and TCXO.
Major power components are :
PM6658 : Phone power supply
AAT3157ITP-T1 : LCD Backlight/Flash charge pump
3.8.2 PM6658
A functional block diagram for the PM6658 device is shown in Figure 1.10.
The input power management portion accepts power from common sources - battery, external
charger, adapter, USB_VBUS, coin cell backup - 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.
The charger pass transistor and current sense resistor are integrated on-chip, thereby reducing the
external parts count and required PCB area.
A configurable option allows the external USB supply to be monitored continuously. If an over-voltage
condition occurs, the PMIC drives the gate control signal (USB_OVP_G) to open an external N-
channel MOSFET, thereby disconnecting the handset's USB circuits from the external device. The
benefits of this added capability includes:
1. Allows connection of non-standard USB devices (such as wall-chargers and carkits) to the
USB_VBUS pin if their operating voltage is within the proper range.
2. Allows the use of a single phone connector for both charging and USB functions.
3. Eliminates external over-voltage protection circuits
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Only for training and service purposes
3. TECHNICAL BRIEF
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