AB1811-T3 ABRACON, AB1811-T3 Datasheet - Page 5

• Manufacturer Part Number: AB1811-T3
• Description: Real Time Clock Interface SPI HH
• Manufacturer: ABRACON

Specifications of AB1811-T3

• Rohs: yes
• Function: Clock, Calendar, Alarm
• Rtc Bus Interface: SPI
• Time Format: HH
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 1.7 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-16

3.2
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.
3.3
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.
3.4
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.
Date of Issue: Sept. 10
VCC Power Switched
Reset Driven
Battery Backup
Page (4) of (13)
Supercap
Backup
th
, 2012
AB18XX
AM18XX
VSS
AB18XX
AM18XX
XO
XI
VBAT
VSS
VSS
FOUT/nIRQ
PSW/nIRQ2
PSW/nIRQ2
FOUT/nIRQ
AM18XX
AB18XX
VCC
Real Time Clock Module
VCC
nRST
VCC
Abracon Drawing #
AB18XX Series
I2C/SPI
3.0 x 3.0 mm
I2C/SPI
I2C/SPI
R
VSS
IRQ
RESET
VSS
VSS
IRQ
MCU
VCC
MCU
VCC
MCU
VCC
T
Revision #: Initial Release
Battery
Main
ESD Sensitive