AB18XX Datasheet, PDF (5/13 Pages) Abracon Corporation – The Abracon Corporation AB18XX Real Time Clock with Power Management family provides a groundbreaking combination of ultra-low power coupled with a highly sophisticated feature set.

Date of Issue: Sept. 10^th, 2012
Page (4) of (13)
AB18XX Series
Real Time Clock Module
3.0 x 3.0 mm
Abracon Drawing #
ESD Sensitive
Revision #: Initial Release
3.2 VCC Power Switched
An external transistor switch T may also be used to turn off power to the MCU. This implementation allows switching
higher current and maintains a common ground. R can be on the order of megohms, so that negligible current is drawn when
the circuit is active and PSW/nIRQ2 is low.
VCC
AB_M1₁8₈X_XX_X
FOUT/nIRQ
PSW/nIRQ2
VSS
R
I2C/SPI
T
VCC
MCU
IRQ
VSS
3.3 Reset Driven
In another implementation the AB18XX controls the system MCU using the reset function rather than switching power.
Since many MCUs use much less power when reset, this implementation can save system power in some cases.
VCC
AABM118X8XX
VSS
nRST
I2C/SPI
RESET
VSS
VCC
MCU
3.4 Battery Backup
In many systems the main power supply is a battery, so the AB18XX can minimize its current draw by powering down the
MCU and other peripherals. This battery may be replaceable, and a supercapacitor charged via the AB18XX trickle charger
can maintain system time and key parameters when the main battery is removed.
Backup
Supercap
VBAT
VCC
I2C/SPI
XO
AMB1188XXXX
FOUT/nIRQ
XI
PSW/nIRQ2
VSS
IRQ
VSS
VCC
MCU
Main
Battery