®
IDT 1337, 1338 & 1339 SERIAL REAL-TIME CLOCKS FLYER
General Description
Integrated Device Technology Inc. introduces its first series of ultra low-power real-time clocks (RTC):
IDT1337, IDT1338, and IDT1339. All three devices offer fast and standard I2C interface, time and date
function, and are available in a variety of packages, making them cost-effective. These devices are suitable
for applications that require minimum board space. By offering high noise immunity, low current consumption,
12/24 hour mode of operation, auto correction for leap year and programmable square wave output —
they are ideal for a wide range of design applications. IDT RTC devices operate over an extended supply
voltage range of 1.8V to 5.5V, a temperature range of -40°C to +85°C, and consume less than 1 μA
current, thus enabling long battery life. The lowest time keeping voltage is 1.3V. The chart below provides
an overview of additional features and benefits of the IDT1337, IDT1338 and IDT1339 real-time clocks.
IDT® 1337, 1338 & 1339 SERIAL REAL-TIME CLOCKS FLYER
IDT 1337, 1338 & 1339
I2C Serial Real-Time Clocks
Low-power, flexible and reliable clock devices enable efficient and cost-effective designs
Benefits Features 1337
1338-18
1338-31
1339-2
1339-31
Ideal for wide range of
design applications
Real-Time Clock (RTC) counts seconds, minutes, hours, day, date, month, and year with
leap-year compensation valid up to 2100 (auto correction for leap year)
4 4 4
12/24 hour mode of operation with AM/PM indicator 444
End of month date adjusted for months fewer than 31 days, including corrections for leap years 444
High noise immunity 444
Programmable square-wave output (on 1337, defaults to 32 kHz on power-up) 444
Full binary-coded decimal (BCD) clock/calendar 444
Two programmable time-of-day alarms 4 4
Oscillator Stop-Flag 444
Package Available in a variety of packages: 8-pin MSOP, 8-pin SOIC, or 16-pin SOIC (surface-mount
package with an integrated crystal)
444
Enables long battery life Consumes less than 1 μA current 444
Low power, low current consumption clock/date device 444
VCC operating
voltage range
1.8V to 5.5V 41338-18 1339-2
2.7V to 5.5V 1338-31 1339-31
Time keeping voltage 1.3V minimum 444
Operating temperature Industrial temperature range (-40°C to +85°C) 444
Suitable for wide range of
applications where minimal
board space is essential
I2C Serial bus interface 444
Integrated 32 kHz crystal 16 pin SOIC package only 444
Battery backup and
data storage
Automatic power-fail detect and switch circuitry (backup battery to the main VCC),
maintaining time/date operation
4 4
56-byte battery-backed NV SRAM for data storage to main VCC 4
Trickle charge capability 4
Applications
•Handhelds(GPS,POSterminals,MP3players)
•ConsumerElectronics(set-topbox,digitalrecording)
•Ofce(fax,printers,copiers)
•Medical(glucometer,medicinedispensers)
•Telecom(routers,switches,servers,network
applications)
•Other(thermostats,vendingmachines,modems,
utility meters, digital photo frames, white goods)
GND
INTA
X2
X1
5
6
7
8
SDA
SCL
SQW/INTB
VCC
(8-pin MSOP and SOIC)
4
3
2
1
®
IDT1337
PIN Assignment
(16-pin SOIC, 300 mil)
SCL 16 SDA
1
NC 13 NC
4
NC 12 NC
5
NC 11 NC
6
NC 10 NC
7
NC 9NC
8
®
IDT1337 15 GND
2
SQW/INTB
VCC 143 INTA
PIN Assignment
GND
VBAT
X2
X1
5
6
7
8
SDA
SCL
SQW/OUT
VCC
(8-pin MSOP and SOIC)
4
3
2
1
®
IDT1338
NC
NC
VCC
SQW/OUT
SCL
NC
NC
NC
12
13
14
15
16
9
10
11
NC
NC
VBAT
GND
SDA
(16-pin SOIC, 300 mil)
NC
NC
NC
5
4
3
2
1
8
7
6
®
IDT1338
PIN Assignment
PIN Assignment
GND
VBACKUP
X2
X1
5
6
7
8
SDA
SCL
SQW/INT
VCC
(8-pin MSOP and SOIC)
4
3
2
1
®
IDT1339
NC
NC
VCC
SCL
NC
NC
NC
12
13
14
15
16
9
10
11
NC
NC
VBACKUP
GND
SDA
(16-pin SOIC, 300 mil)
NC
NC
NC
5
4
3
2
1
8
7
6
®
IDT1339
SQW/INT
PIN Assignment
PIN Assignment
I2C Serial Real-Time Clock
IDT1337
IDT1338
IDT1339
®
SQW/OUT
X1
X2
Mux/
Buffer
1 Hz
1 Hz/4.096 kHz/8.192 kHz/32.768 kHz
User Buffer
(7 bytes)
Control
Logic
Serial Bus
Interface and
Address Register
Vcc
CL
CL
VBAT
GND
16-pin SOIC version
only (included in
the package)
SCL
SDA
Oscillator
and Divider
Power Control
(1338 & 1339 only)
Clock, Calendar
and
Control Registers
(1337, 1338, and 1339)
Alarms
(1337 and 1339)
Trickle Charge
(1339 Only)
RAM (56x8)
(1338 Only)
®
© 2008 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are registered trademarks of Integrated Device
Technology, Inc. All other brands, product names and marks are or may be trademarks or registered trademarks used to identify products or services of their respective owners.
Printed in USA 5-08/MG/KIP/HOP/1K FLYR-RTC-058
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