DS1341_12 Datasheet, PDF (4/16 Pages) Maxim Integrated Products – Low-Current I2C RTCs for High-ESR Crystals

Low-Current I²C RTCs for High-ESR Crystals
Note 11: CB is the total capacitance of one bus line, including all connected devices, in pF.
Note 12: Guaranteed by design; not 100% production tested.
Note 13: The parameter tOSF is the period of time the oscillator must be stopped for the OSF flag to be set over the voltage
range of 2.4V P VCC P VCCMAX.
Note 14: The DS1341/DS1342 can detect any single SCL clock held low longer than tTIMEOUTMIN. The devices’ I²C interface is
in reset state and can receive a new START condition when SCL is held low for at least tTIMEOUTMAX. Once the device
detects this condition, the SDA output is released. The oscillator must be running for this function to work.
SDA
tBUF
tLOW
SCL
tHD:STA
tR
STOP
START
NOTE: TIMING IS REFERENCED TO V_ILMAX AND V_IHMIN.
tHD:DAT
tF
tHIGH
tSU:DAT
Figure 1. Data Transfer on I²C Serial Bus
tHD:STA
tSU:STA
REPEATED
START
tSP
tSU:STO
Functional Diagram
VCC
DS1341/DS1342
32.768kHz
P
8.192kHz
4.096kHz
MUX/
BUFFER
SQW/INTB
128Hz
OSC-1Hz
X1
/4
/2
/32
EXTSYNC
N
EXT-1Hz
DIVIDER
X2
CONTROL LOGIC
CLKIN/INTA
SCL
SERIAL BUS
SDA
INTERFACE AND
ADDRESS
REGISTER
N
ALARM AND
CONTROL REGISTERS
N
OSC-1Hz
CLOCK AND
CALENDAR REGISTERS
4