The DS1375 digital real-time clock (RTC) is a low-power
clock/calendar that does not require a crystal. The
device operates from a digital clock input pin at one of
four frequencies: 32.768kHz, 8.192kHz, 60Hz, or 50Hz.
It maintains seconds, minutes, hours, day, date, month,
and year information. The date at the end of the month
is automatically adjusted for months with fewer than 31
days, including corrections for leap year. The clock
operates in either the 24-hour or 12-hour format with an
AM/PM indicator. Two programmable time-of-day/date
alarms, a programmable square-wave output, and 16
bytes of SRAM are provided. Address and data are
transferred serially through an I
2
C bidirectional bus.
Features
♦
RTC Counts Seconds, Minutes, Hours, Day, Date,
Month, and Year with Leap-Year Compensation
Valid Up to 2100
♦
Two Programmable Alarms
♦
Programmable Square-Wave Output
♦
Operates from a 32.768kHz, 8.192kHz, 60Hz, or
50Hz Digital Clock Signal
♦
16 Bytes of SRAM
♦
Fast (400kHz) I
2
C Interface
♦
1.7V to 5.5V Operation
DS1375
Applications
RTC Complement to the DS32kHz TCXO
Utility Meters
Appliances
Consumer Electronics
Automotive
PART
DS1375T+
Ordering Information
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE TOP MARK
6 TDFN-EP*
DS1375
+Denotes
a lead-free/RoHS-compliant package.
*EP
= Exposed pad.
Typical Operating Circuit
TOP VIEW
+3V
RPU = t
r
/C
B
Pin Configuration
RPU
RPU
+
CLK
V
CC
SCL
SCA
CLK
V
BAT
V
CC
1
6
V
CC
SCL
SQW/INT
2
DS1375
*EP
5
CPU
DS1375
INT
SQWINT
DS32kHz
GND
3
4
SDA
GND
GND
TDFN
(3mm
×
3mm)
*EXPOSED PAD
______________________________________________
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.
I
2
C Digital Input RTC with Alarm
DS1375
ABSOLUTE MAXIMUM RATINGS
Voltage Range on V
CC
Pin
Relative to Ground.............................................-0.3V to +6.0V
Voltage Range on SDA, SCL, and WDS
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...........................Refer to the 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.
RECOMMENDED DC OPERATING CONDITIONS
(V
CC
= +1.7V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
CC
= 3.3V, T
A
= +25°C, unless other-
wise noted.) (Note 1)
PARAMETER
Supply Voltage
Timekeeping Voltage
Input Logic 1 (SDA, SCL)
Supply Voltage, Pullup
(SQW/INT, CLK)
Input Logic 0
Input Leakage (SCL, CLK)
I/O Leakage (SDA, SQW/INT)
SDA Logic 0 Output
SYMBOL
V
CC
V
TK
V
IH
V
PULLUP
V
IL
I
LI
I
LO
I
OLSDA
V
CC
> 2V; V
OL
= 0.4V
V
CC
< 2V; V
OL
= 0.2 x V
CC
V
CC
> 2V; V
OL
= 0.4V
SQW/INT Logic 0 Output
Active Supply Current
Standby Current
I
OLSQW
I
CCA
I
CCS
1.7V < V
CC
< 2V; V
OL
= 0.2 x V
CC
1.3V < V
CC
< 1.7V; V
OL
= 0.2 x V
CC
(Notes 5, 6)
(Notes 6, 7)
33
150
(Note 2)
(Note 2)
(Note 2)
(Notes 2, 3)
(Notes 2, 4)
-0.3
-1
-1
CONDITIONS
MIN
1.7
1.3
0.7 x V
CC
TYP
3.3
MAX
5.5
5.5
V
CC
+ 0.3
5.5
+0.3
V
CC
+1
+1
3.0
3.0
250
150
500
UNITS
V
V
V
V
V
µA
µA
mA
mA
µA
µA
nA
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Limits at -40°C are guaranteed by design and not production tested.
All voltages are referenced to ground.
For the CLK pin, input voltages above V
CC
+ 0.3V cause current to flow into the device. The input current must not
exceed the current drawn by the circuit that is connected to V
CC
. Otherwise, current flows out of the DS1375, raising the
voltage level on the V
CC
bus.
V
IL MIN
on the CLK pin can exceed -0.3V as long as the current is limited to less than 1mA.
I
CCA
—SCL clocking at max frequency = 400kHz.
CLK pin running at 32,768Hz, rise and fall times at 10ns or less.
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