Power On/Off; Only For Training And Service Purposes - LG KC780 Service Manual

3. TECHNICAL BRIEF
b. Dedicated : 3.51V~3.41V
10. Low battery alarm interval
a. Idle : 3min
b. Dedicated:1min
11. Switch-off voltage : 3.35V
12. Charging temperature adc range
a. ~ -20 ℃ low charging voltage operation (3.8V ~ 4.0V) . :
b. -20 ℃ ~ 60 ℃ standard charging (up to 4.2 V)
c.
60 ~ ℃ : low charging voltage operation (3.8V ~ 4.0V)

3.5. Power ON/OFF

3.5.1 ON/OFF Switching Sequence
After the ON-trigger (either from ON_OFF1/2 pin or charger) SGR PMU Subsystem follows a well-defined
startup sequence to ensure a proper system start up.
State power supply is connected and ON is triggered: (enter point of System Startup State
Machine)
• ON_OFF1 is low (or ON_OFF2 is high, or VCH>3.2V)
• VRTC is active
• I2C_INT is high
• On-chip oscillator calibrated and running, reference and bias calibrated and running
Startup Sequence from System Startup State Machine
• Start SD1 in active mode
• After time TE1 start SD2 in active mode
• After T delay, start LDOs in the sequence: VRF1, VIO, VPLL, VAUX (all started with delay to each
DEL1
other)
• After TE2 delay (settling of the DCXO) force signal I2C_INT to low. Comparator for VAUX voltage
supervision
is enabled
• After TE3 (settling S-GOLDradio Power Management Unit GPIOs) RESET_N/RESET2_N are released
LGE Internal Use Only
:
- 36 - Copyright © 2008 LG Electronics. Inc. All right reserved.

Only for training and service purposes