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 I
2
C
*
bidirectional bus.
Features
♦
Enhanced Second Source for the ST M41T00
♦
Available in a Surface-Mount Package with an
Integrated Crystal (DS1340C)
♦
Fast (400kHz) I
2
C 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
DS1340
Applications
Portable Instruments
Point-of-Sale Equipment
Medical Equipment
Telecommunications
PART
DS1340Z-18
DS1340Z-3
DS1340Z-33
DS1340U-18
DS1340U-3
DS1340U-33
V
CC
CRYSTAL
V
CC
R
PU
R
PU
1
X1
6 SCL
CPU
2
X2
8
V
CC
FT/OUT
7
C1
V
CC
Ordering Information
TEMP RANGE PIN-PACKAGE
-40°C to +85°C 8 SO (0.150in)
-40°C to +85°C 8 SO (0.150in)
-40°C to +85°C 8 SO (0.150in)
-40°C to +85°C 8 µSOP
-40°C to +85°C 8 µSOP
-40°C to +85°C 8 µSOP
-40°C to +85°C 16 SO
-40°C to +85°C 16 SO
-40°C to +85°C 16 SO
-40°C to +85°C 8 SO (0.150in)
-40°C to +85°C 8 SO (0.150in)
-40°C to +85°C 8 SO (0.150in)
-40°C to +85°C 8 µSOP
-40°C to +85°C 16 SO
-40°C to +85°C 16 SO
-40°C to +85°C 16 SO
TOP
MARK
†
D1340-18
DS1340-3
D1340-33
1340A1-18
1340A1-3
1340A1-33
1340C-18
1340C-3
1340C-33
D1340-18
DS1340-3
D1340-33
1340A1-18
1340A1-3
1340A1-33
1340C-18
1340C-3
1340C-33
Typical Operating Circuit
DS1340C-18
DS1340C-3
DS1340C-33
DS1340Z-18+
DS1340Z-3+
DS1340Z-33+
DS1340U-3+
DS1340C-18#
DS1340C-3#
DS1340C-33#
DS1340U-18+ -40°C to +85°C 8 µSOP
DS1340
5 SDA
R
PU
= t
R
/ C
B
GND
4
V
BACKUP
3
DS1340U-33+ -40°C to +85°C 8 µSOP
+
Denotes a lead-free/RoHS-compliant device.
*Purchase
of I
2
C components from Maxim Integrated Products,
Inc., or one of its sublicensed Associated Companies, conveys
a license under the Philips I
2
C Patent Rights to use these com-
ponents in an I
2
C system, provided that the system conforms to
the I
2
C Standard Specification as defined by Philips.
#
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.
I
2
C RTC with Trickle Charger
DS1340
ABSOLUTE MAXIMUM RATINGS
Voltage Range on V
CC
Pin Relative to Ground .....-0.3V to +6.0V
Voltage Range on SDA, SCL, and FT/OUT
Relative to Ground..................................-0.3V to (V
CC
+ 0.3V)
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-55°C to +125°C
Soldering Temperature Range............................See IPC/JEDEC
J-STD-020 Specification
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
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