DS1340_06 Datasheet, PDF (1/14 Pages) Maxim Integrated Products – I2C RTC with Trickle Charger

Rev 4; 3/06
I²C RTC with Trickle Charger
General Description
The DS1340 is a real-time clock (RTC)/calendar that is
pin compatible and functionally equivalent to the ST
M41T00, including the software clock calibration. The
device additionally provides trickle-charge capability
on the V_BACKUP pin, a lower timekeeping voltage, and
an oscillator STOP flag. Block access of the register
map is identical to the ST device. Two additional regis-
ters, which are accessed individually, are required for
the trickle charger and flag. The clock/calendar pro-
vides seconds, minutes, hours, day, date, month, and
year information. A built-in power-sense circuit detects
power failures and automatically switches to the back-
up supply. Reads and writes are inhibited while the
clock continues to run. The device is programmed seri-
ally through an I²C^* bidirectional bus.
Portable Instruments
Point-of-Sale Equipment
Medical Equipment
Telecommunications
Applications
Typical Operating Circuit
V_CC
V_CC
CRYSTAL
V_{CC RPU}
R_PU
1
2
8
C1
X1 X2
6 _SCL
V_CC
7
FT/OUT
CPU
R_PU = t_R / C_B
5 _SDA
DS1340
3
V_BACKUP
GND
4
*Purchase of I²C components from Maxim Integrated Products,
Inc., or one of its sublicensed Associated Companies, conveys
a license under the Philips I²C Patent Rights to use these com-
ponents in an I²C system, provided that the system conforms to
the I²C Standard Specification as defined by Philips.
Features
♦ Enhanced Second Source for the ST M41T00
♦ Available in a Surface-Mount Package with an
Integrated Crystal (DS1340C)
♦ Fast (400kHz) I²C Interface
♦ Software Clock Calibration
♦ RTC Counts Seconds, Minutes, Hours, Day, Date,
Month, and Year
♦ Automatic Power-Fail Detect and Switch Circuitry
♦ Trickle-Charge Capability
♦ Low Timekeeping Voltage Down to 1.3V
♦ Three Operating Voltage Ranges (1.8V, 3V, and 3.3V)
♦ Oscillator Stop Flag
♦ Available in 8-Pin µSOP or SO Packages
♦ Underwriters Laboratory (UL) Recognized
Ordering Information
PART
DS1340Z-18
DS1340Z-3
DS1340Z-33
DS1340U-18
DS1340U-3
DS1340U-33
DS1340C-18
DS1340C-3
DS1340C-33
DS1340Z-18+
TEMP RANGE
PIN-PACKAGE
TOP
MARK^†
-40°C to +85°C 8 SO (0.150in) D1340-18
-40°C to +85°C 8 SO (0.150in) DS1340-3
-40°C to +85°C 8 SO (0.150in) D1340-33
-40°C to +85°C 8 µSOP
1340A1-18
-40°C to +85°C 8 µSOP
1340A1-3
-40°C to +85°C 8 µSOP
1340A1-33
-40°C to +85°C 16 SO
1340C-18
-40°C to +85°C 16 SO
1340C-3
-40°C to +85°C 16 SO
1340C-33
-40°C to +85°C 8 SO (0.150in) D1340-18
DS1340Z-3+ -40°C to +85°C 8 SO (0.150in)
DS1340Z-33+ -40°C to +85°C 8 SO (0.150in)
DS1340U-18+ -40°C to +85°C 8 µSOP
DS1340U-3+ -40°C to +85°C 8 µSOP
DS1340U-33+ -40°C to +85°C 8 µSOP
DS1340-3
D1340-33
1340A1-18
1340A1-3
1340A1-33
DS1340C-18# -40°C to +85°C 16 SO
DS1340C-3# -40°C to +85°C 16 SO
1340C-18
1340C-3
DS1340C-33# -40°C to +85°C 16 SO
1340C-33
+ Denotes a lead-free/RoHS-compliant device.
# Denotes a RoHS-compliant device that may include lead that
is exempt under RoHS requirements. The lead finish is JESD97
category e3, and is compatible with both lead-based and lead-
free soldering processes.
† A "+" anywhere on the top mark denotes a lead-free device.
A "#" denotes a RoHS-compliant device.
Pin Configurations appear at end of data sheet.
______________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.