Power Management - LG GU280 Service Manual

3.7 Power management

3.7.1 Input power management
Valid external supply attachment and removal detection
Unregulated (closed-loop) external charger supply as input power source
Integrated PFET charging pass transistor; eliminated sense resistor
Support for lithium-ion and lithium-ion polymer main batteries; nickel-based batteries are not supported
Trickle, constant current, constant voltage, and pulse charging of the main battery
Autonomous charging option – driven by an on-chip state machine without software intervention
Software-controlled charging option – backwards-compatible with previous QSC and PM products
Coin-cell battery (including charging)
Battery-voltage detectors with programmable thresholds
VDD collapse protection
Charger-current regulation and real-time monitoring for overcurrent protection
Charger-transistor protection by thermal control
Control drivers for the internal charging PFET and external battery PFET
Voltage, current, and thermal control loops
Automated recovery from sudden momentary power loss (requires external32.768 kHz crystal)
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Only for training and service purposes
Figure 2.2.1 Input circuits schematic diagram
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3. Technical Brief
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