AB08X5 Real-Time Clock Family

Date of Issue: October 16, 2014

3.0 x 3.0 mm

Page 3 of 33

Abracon Drawing #453567

Revision: C

2. Functional Description

Figure 1 illustrates the AB08X5 functional design.

Figure 1. Detailed Block Diagram

The AB08X5 serves as a full function RTC for host processors such as microcontrollers. The AB08X5

includes 3 distinct feature groups: 1) baseline timekeeping features, 2) advanced timekeeping features,

and 3) basic power management features. Functions from each feature group may be controlled via I/O

AB0805) or a SPI serial interface (e.g., in the AB0815). Each feature group is described briefly below and

in greater detail in subsequent sections.

The baseline timekeeping feature group supports the standard 32.786 kHz crystal (XT) oscillation mode for

maximum frequency accuracy with an ultra-low current draw of 55 nA. The baseline timekeeping feature

group also includes a standard set of counters monitoring hundredths of a second up through centuries. A

complement of countdown timers and alarms may additionally be set to initiate interrupts or resets on

several of the outputs.

XT Osc

RC Osc

Divider

Seconds

Minutes

Hours

Days

Weekdays

Months

Years

Power

Control

VCC VBAT

I2C/SPI

Interface

SCL

SDA/O

Control

Alarms

Int/Clock

FOUT/nIRQ

nIRQ2

VSS

SDI

nCE

WDI

RAM

XO

XI

nTIRQ

Timer

WDT

100ths

Divider

Calibration Engine

EXTI

Analog

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