DS1347_1202 Datasheet, PDF (1/17 Pages) Maxim Integrated Products – Low-Current, SPI-Compatible Real-Time Clock

19-6007; Rev 2; 2/12
Low-Current, SPI-Compatible Real-Time Clock
General Description
The DS1347 SPI-compatible real-time clock (RTC) con-
tains a real-time clock/calendar and 31 x 8 bits of static
random-access memory (SRAM). The real-time
clock/calendar provides seconds, minutes, hours, day,
date, month, year, and century information. A time/date
programmable polled ALARM is included in the device.
The end-of-the-month date is automatically adjusted for
months with fewer than 31 days, including corrections
for leap year. The clock operates in either the 24hr or
12hr format with an AM/PM indicator. The device oper-
ates with a supply voltage of +2V to +5.5V, are avail-
able in the ultra-small 8-pin TDFN package, and work
over the -40°C to +85°C industrial temperature range.
Point-of-Sale Equipment
Intelligent Instruments
Fax Machines
Battery-Powered Products
Portable Instruments
Applications
Ordering Information
PART
TEMP RANGE ^{OSC CL} PIN-PACKAGE
(pF)
DS1347T+ -40°C to +85°C 12.5 8 TDFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Features
o RTC Counts Seconds, Minutes, Hours, Day of Week,
Date of Month, Month, Year, and Century
o Leap-Year Compensation
o +2V to +5.5V Wide Operating Voltage Range
o SPI (Mode 1 or 3) Interface: 4MHz at 5V, 1MHz at 2V
o 31 x 8-Bit SRAM for Scratchpad Data Storage
o Uses Standard 32.768kHz Watch Crystal
o Low Timekeeping Current (400nA at 2V)
o Single-Byte or Multiple-Byte (Burst Mode) Data
Transfer for Read or Write of Clock Registers or
SRAM
o Ultra-Small, 3mm x 3mm x 0.8mm, 8-Pin TDFN
Package
o Programmable Time/Date Polled ALARM Function
o No External Crystal Bias Resistors or Capacitors
Required
Typical Operating Circuit
+3.3V
µc
+3.3V _0.1µF
6
V_CC
DS1347 ^{X1 8}
1 _SCLK
5 _CS
2 _DOUT
3 _DIN
GND
4
X2 ⁷
32.768kHz
CRYSTAL
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.