LP3910 Datasheet, PDF (45/72 Pages) Texas Instruments – Power Management IC for Hard-Drive-Based Portable Media Players

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Device Functional Modes (continued)
LP3910
SNVS481M – NOVEMBER 2006 – REVISED DECEMBER 2015
Vterm
4.2V (Typ.)
Active
VBLA
2.4-3.5V (factory
programmable)
Vuvlo
2.4V (Typ.)
2.1V
Vpor
0.9V
Battery safety switch on/off threshold
Standby
PowerOff
Figure 65. Voltage Threshold Levels
LDO1,2
Buck1,2
Buck-Boost
Charger
ADC
NRST
I²C interface
Internal system oscillator
Battery monitor
Current consumption
POWER OFF
Off
Off
Off
Off
Off
Low
Off
Off
Off
<1 µA
Table 8. Power State Table
STANDBY
Off
Off
Off
Off
Off
Low
Off
Off
On
10 µA (typical)
ACTIVE
On
On
On
On if Charger / USB
Present
On
High
On
On
On
See Specifications
CHARGER STANDBY
Off
Off
Off
On if Charger / USB
Present
Off
Low
On
On
On
See Specifications
8.4.1.1 Power-Off Mode
In power-off mode the main battery, the battery charger supply, and the USB supply are below their minimum on
levels. All internal circuits are disabled as the supply voltage is below the level to activate them. The LP3910 is in
power-off mode when the battery voltage is below the battery V_UVLO (2.4 V, typical) except when a valid external
supply is detected.
8.4.1.2 Standby Mode
When the LP3910 is in standby mode, the chip is waiting for a valid power-on event to transition to active mode.
There are 3 valid wake-up signals. First is the ONOFF pin. Second is wall adapter insertion. Third is the USB
insertion. V_BATT must be greater than the battery V_UVLO in order to stay in standby mode; otherwise, the chip
transitions to power-off mode. Standby mode is skipped when advancing from power-off mode when a battery is
inserted that is above the battery low alarm threshold.
If the battery is below the battery low alarm threshold, power-off mode transitions to standby mode. However, hot
insertion of the battery with the adapter connected is NOT permitted. In standby mode, the current consumption
is reduced to I_Q (10 µA, typical).
8.4.1.3 Active Mode
All LP3910 circuits are fully operational in active mode.
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