LP3910 Datasheet, PDF (39/72 Pages) Texas Instruments – Power Management IC for Hard-Drive-Based Portable Media Players

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LP3910
SNVS481M – NOVEMBER 2006 – REVISED DECEMBER 2015
As new interrupts can occur while the I²C read cycle is clearing the IRQ register, a buffer register called interrupt
pending register (IPR), not accessible through the I²C-compatible interface holds the next interrupts. De-
asserting the IRQB output is immediately followed by a new transition of IRQB to logic low when an interrupt is
pending.
The Interrupts are not hardware prioritized. It is up to the firmware to determine the priority in case more than
one interrupt request is set.
IRQB
IMR
IRQ
int0
int1
int2
int3
Interrupt
sources
CHG_IN power
detected
CHG_IN power
removed
USB Power
detected
USB Power
removed
int4
Battery Low
int5
Thermal alarm
int6
int7
Interrupt
Pending
register
ADC conversion completed
Charger
safety timer
timeout
Figure 61. Interrupt Request Setting
8.3.6.1 Interrupts and Standby Mode
Interrupts are captured in standby mode and can be serviced when the system processor is enabled when the
LP3910 is in an active state.
8.3.6.2 Interrupt Sources
• CHG_IN Power Detected and CHG_IN Disconnect (INT0 and INT1): An interrupt (INT0) is generated when
CHG_IN power is connected to the LP3910. Another interrupt (INT1) is generated upon CHG_IN power
removal.
• USB Power Detected and USB Disconnect (INT2 and INT3): An interrupt (INT2) is generated when USB
power is connected to the LP3910. Another interrupt (INT3) is generated upon disconnecting the USB power.
• Battery Low (INT4): When the battery voltage drops below the battery low threshold IRQ, an interrupt is
generated. This allows the processor to perform some routine tasks prior to going to standby mode.
• Thermal Alarm (INT5): If the junction temperature of the LP3910 exceeds 115°C, an interrupt is generated.
• ADC Conversion Done (INT6): The ADC generates an interrupt request upon the completion of a data
conversion.
• Charger Timer Interrupt (INT7): A charger timeout occurs 10 hours after it started (see Li-Ion Linear Charger)
and subsequently requests an interrupt.
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