Baseband Processor (Ad6721 , U103) - LG KG290 Service Manual

3. TECHNICAL BRIEF
E. LDO Block
There are 8 LDOs in the AD6721.
- VCORE : supplies Digital baseband Processor core and AD6721 digital core
- VMEM : supplies external memory and the interface to the external memory on the digital
baseband processor (1,8V or 2.8V, 150mA)
- VEXT : supplies Radio digital interface and high voltage interface (2.8V, 170mA)
- VSIM : supplies the SIM interface circuitry on the digital processor and SIM card (2.85V, 20mA)
- VRTC : supplies the Real-Time Clock module (1.8 V, 20 µA)
- VABB : supplies the analog portions of the AD6721
- VMIC : supplies the microphone interface circuitry (2.5 V, 1 mA)
- VVCXO : supplies the voltage controlled crystal oscillator ( 2.75 V, 10 mA)
3.6 Battery Charging Block
1. Charging method : CC-CV
2.Charger detect voltage : 4.0V
3.Charging time : 3h
4.Charging current : 500mA
5.CV voltage : 4.2V
6.Cutoff current : 100mA
7.Full charge indication current (icon stop current) : 100mA
8.Recharge voltage : 4.00V
9.Low battery alarm
a. Idle : 3.50V~3.35V
b. Dedicated : 3.56V~3.35V
Low battery alarm interval
Idle : 3min
Dedicated:1min
Switch-off voltage : 3.35V
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