DS1339U-33+T&R ,I²C Serial Real-Time ClockELECTRICAL CHARACTERISTICS (V = MIN to MAX, T = -40°C to +85°C.) (Note 2) CC APARAMETER SYMBOL COND ..
DS1339U-33+T&R ,I²C Serial Real-Time Clock DS1339 2I C Serial Real-Time Clock
DS1340C-18+ ,I2C RTC with Trickle ChargerDS1340Rev 2; 12/042I C RTC with Trickle Charger
DS1340C-3+ ,I2C RTC with Trickle ChargerApplicationsOrdering InformationPortable InstrumentsPoint-of-Sale EquipmentTOPPART TEMP RANGE PIN-P ..
DS1340C-33 ,I2C RTC with Trickle ChargerDS1340Rev 2; 12/042I C RTC with Trickle Charger
DS1340C-33# ,I²C RTC with Trickle ChargerFeaturesThe DS1340 is a real-time clock (RTC)/calendar that is • Enhanced Second Source for the ST ..
DTC124XM , 100mA / 50V Digital transistors (with built-in resistors)
DTC124XS , DTA/DTC SERIES
DTC124XSA , Digital transistors (built-in resistors)
DTC143 , NPN Small Signal Transistor Small Signal Diode
DTC143ECA ,Conductor Holdings Limited - Digital Transistor
DTC143ECA ,Conductor Holdings Limited - Digital Transistor
DS1339C-3#-DS1339C-33#-DS1339U-33+T&R
I²C Serial Real-Time Clock
GENERAL DESCRIPTION The DS1339 serial real-time clock (RTC) is a low-
power clock/date device with two programmable time-
of-day alarms and a programmable square-wave
output. Address and data are transferred serially
through an I2C bus. The clock/date provides 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
AM/PM indicator. The DS1339 has a built-in power-
sense circuit that detects power failures and
automatically switches to the backup supply,
maintaining time, date, and alarm operation.
APPLICATIONS Handhelds (GPS, POS Terminals)
Consumer Electronics (Set-Top Box, Digital
Recording, Network Appliance)
Office Equipment (Fax/Printers, Copier)
Medical (Glucometer, Medicine Dispenser)
Telecommunications (Routers, Switches, Servers)
Other (Utility Meter, Vending Machine, Thermostat,
Modem)
Pin Configurations appear at end of data sheet.
BENEFITS AND FEATURES Completely Manages All Timekeeping
Functions Real-Time Clock Counts Seconds,
Minutes, Hours, Date of the Month,
Month, Day of the Week, and Year
with Leap-Year Compensation Valid
Up to 2100 Two Time-of-Day Alarms Programmable Square-Wave Output Oscillator Stop Flag Interfaces to Most Microcontrollers I2C Serial Interface Low-Power Operation Extends Battery
Backup Run Time Automatic Power-Fail Detect and
Switch Circuitry Trickle-Charge Capability Underwriters Laboratories® (UL)
Recognized Surface-Mount Package with an
Integrated Crystal (DS1339C Saves
Additional Space and Simplifies Design
ORDERING INFORMATION
PART TEMP RANGE VOLTAGE (V) PIN-PACKAGE TOP MARK† DS1339C-2# -40°C to +85°C 2.0 16 SO (300 mils) DS1339C-2
DS1339C-3# -40°C to +85°C 3.0 16 SO (300 mils) DS1339C-3
DS1339C-33# -40°C to +85°C 3.3 16 SO (300 mils) DS1339C-33
DS1339U-2+ -40°C to +85°C 2.0 8 µSOP 1339 rr-2
DS1339U-3+ -40°C to +85°C 3.0 8 µSOP 1339 rr-3
DS1339U-33+ -40°C to +85°C 3.3 8 µSOP 1339 rr-33
+Denotes a lead(Pb)-free/RoHS-compliant package.
#Denotes a RoHS-compliant device that may include lead that is exempt under the 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 indicates a lead(Pb)-free device. A “#” denotes a RoHS-compliant device. rr = second line, revision code
DS1339 2C Serial Real-Time Clock
DS1339 I2C Serial Real-Time Clock
ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground………………………………………………………………-0.3V to +6.0V
Operating Temperature Range (Noncondensing)………………………………………………………….-40°C to +85°C
Storage Temperature Range………………………………………………………………………………..-55°C to +125°C
Lead Temperature (soldering, 10s)...…………………………………………………………………………………+260°C
Soldering Temperature (reflow).……………………………………………………………………………………….+260°C
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 the absolute maximum rating conditions for extended periods may affect device reliability.
PACKAGE THERMAL CHARACTERISTICS (Note 1) µSOP Junction-to-Ambient Thermal Resistance (θJA).…………………...……………………………………….206.3°C/W Junction-to-Case Thermal Resistance (θJC)……………………………………………………………………42°C/W
SO Junction-to-Ambient Thermal Resistance (θJA).……………………………………………………………….73°C/W Junction-to-Case Thermal Resistance (θJC)……………………………………………………………………23°C/W
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to /thermal-tutorial.
RECOMMENDED DC OPERATING CONDITIONS (TA = -40°C to +85°C) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage VCC
DS1339-2 1.8 2.0 5.5 DS1339-3 2.7 3.0 5.5
DS1339-33 2.97 3.3 5.5
Backup Supply Voltage VBACKUP 1.3 3.0 3.7 V
Logic 1 VIH 0.7 x
VCC VCC +
0.3 V
Logic 0 VIL -0.3 +0.3 x
VCC V
Power-Fail Voltage VPF
DS1339-2 1.58 1.70 1.80 DS1339-3 2.45 2.59 2.70
DS1339-33 2.70 2.85 2.97
DS1339 I2C Serial Real-Time Clock
DC ELECTRICAL CHARACTERISTICS (VCC = MIN to MAX, TA = -40°C to +85°C.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Leakage ILI (Note 3) 1 µA
I/O Leakage ILO (Note 4) 1 µA
Logic 0 Out
VOL = 0.4V; VCC > VCC MIN (-3, -33);
VCC ≥ 2.0V (-2)
IOL (Note 4) 3 mA
Logic 0 Out
VOL = 0.2 (VCC);
1.8V < VCC < 2.0V (DS1339-2)
IOL (Note 4) 3 mA
Logic 0 Out
VOL = 0.2 (VCC);
1.3V < VCC < 1.8V (DS1339-2)
IOL (Note 4) 250 µA
VCC Active Current ICCA (Note 5) 450 µA
VCC Standby Current (Note 6) ICCS
-2: VCC = 2.2V 60 100 µA -3: VCC = 3.3V 80 150
-33: VCC = 5.5V 200
Trickle-Charger Resistor Register
10h = A5h, VCC = Typ, VBACKUP = 0V R1 (Note 7) 250 Ω
Trickle-Charger Resistor Register
10h = A6h, VCC = Typ, VBACKUP = 0V R2 2000 Ω
Trickle-Charger Resistor Register
10h = A7h, VCC = Typ, VBACKUP = 0V R3 4000 Ω
VBACKUP Leakage Current IBKLKG 25 100 nA
DC ELECTRICAL CHARACTERISTICS (VCC = 0V, TA = -40°C to +85°C.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS VBACKUP Current EOSC = 0, SQW Off IBKOSC (Note 8) 400 700 nA
VBACKUP Current EOSC = 0, SQW On IBKSQW (Note 8) 600 1000 nA
VBACKUP Current EOSC = 1 IBKDR 10 100 nA
DS1339 I2C Serial Real-Time Clock
AC ELECTRICAL CHARACTERISTICS (VCC = MIN to MAX, TA = -40°C to +85°C.) (Note 9)
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS SCL Clock Frequency fSCL
Fast mode 100 400
kHz
Standard mode 100
Bus Free Time Between a STOP
and START Condition tBUF Fast mode 1.3 µs Standard mode 4.7
Hold Time (Repeated) START
Condition (Note 10) tHD:STA Fast mode 0.6 µs Standard mode 4.0
LOW Period of SCL Clock tLOW Fast mode 1.3 µs Standard mode 4.7
HIGH Period of SCL Clock tHIGH Fast mode 0.6 µs Standard mode 4.0
Setup Time for a Repeated
START Condition tSU:STA Fast mode 0.6 µs Standard mode 4.7
Data Hold Time (Notes 11, 12) tHD:DAT Fast mode 0 0.9 µs Standard mode 0
Data Setup Time (Note 13) tSU:DAT Fast mode 100 ns Standard mode 250
Rise Time of Both SDA and SCL
Signals (Note 14) tR Fast mode 20 + 0.1CB 300 ns Standard mode 20 + 0.1CB 1000
Fall Time of Both SDA and SCL
Signals (Note 14) tF Fast mode 20 + 0.1CB 300 ns Standard mode 20 + 0.1CB 300
Setup Time for STOP Condition tSU:STO Fast mode 0.6 µs Standard mode 4.0
Capacitive Load for Each Bus
Line (Note 14) CB 400 pF
I/O Capacitance (SDA, SCL) CI/O (Note 9) 10 pF
Oscillator Stop Flag (OSF) Delay tOSF (Note 15) 100 ms
DS1339 I2C Serial Real-Time Clock
POWER-UP/DOWN CHARACTERISTICS (TA = -40°C to +85°C) (Note 2, Figure 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Recovery at Power-Up tREC (Note 16) 2 ms
VCC Fall Time; VPF(MAX) to VPF(MIN) tVCCF 300 µs
VCC Rise Time; VPF(MIN) to VPF(MAX) tVCCR 0 µs
WARNING: Under no circumstances are negative undershoots, of any amplitude, allowed when device is in
battery-backup mode.
Note 2: Limits at -40°C are guaranteed by design and are not production tested.
Note 3: SCL only.
Note 4: SDA and SQW/INT.
Note 5: ICCA—SCL at fSC max, VIL = 0.0V, VIH = VCC, trickle charger disabled.
Note 6: Specified with the I2C bus inactive, VIL = 0.0V, VIH = VCC, trickle charger disabled.
Note 7: VCC must be less than 3.63V if the 250Ω resistor is selected.
Note 8: Using recommended crystal on X1 and X2.
Note 9: Guaranteed by design; not production tested.
Note 10: After this period, the first clock pulse is generated.
Note 11: A device must internally provide a hold time of at least 300ns for the SDA signal (referred to the VIHMIN of the SCL signal) to bridge
the undefined region of the falling edge of SCL.
Note 12: The maximum tHD:DAT need only be met if the device does not stretch the LOW period (tLOW) of the SCL signal.
Note 13: A fast-mode device can be used in a standard-mode system, but the requirement tSU:DAT ≥ to 250ns must then be met. This is
automatically the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW
period of the SCL signal, it must output the next data bit to the SDA line tR(MAX) + tSU:DAT = 1000 + 250 = 1250ns before the SCL line
is released.
Note 14: CB—total capacitance of one bus line in pF.
Note 15: The parameter tOSF is the period of time the oscillator must be stopped for the OSF flag to be set over the voltage range of 0.0V ≤
VCC ≤ VCCMAX and 1.3V ≤ VBACKUP ≤ 3.7V.
Note 16: This delay applies only if the oscillator is running. If the oscillator is disabled or stopped, no power-up delay occurs.
Figure 1. Power-Up/Down Timing OUTPUTS
VCC V PF(MAX) PF(MIN)
INPUTS
HIGH-Z
DON'T CARE
VALID
RECOGNIZED RECOGNIZED
VALID VCCF t VCCR REC
DS1339 I2C Serial Real-Time Clock
Figure 2. Timing Diagram
Figure 3. Block Diagram ALARM, TRICKLE
CHARGE, AND
CONTROL
REGISTERS
SERIAL BUS
INTERFACE AND
ADDRESS REGISTER
CONTROL LOGIC
1Hz
1Hz/4.096kHz/8.192kHz/32.768kHzMUX/
BUFFER
USER BUFFER (7
BYTES)
CLOCK AND
CALENDAR
REGISTERS
Power ControlX2
DS1339
SQW/INT
VCC
VBACKUP
SCL
SDA
GND
Oscillator
and divider"C" version only
DS1339 I2C Serial Real-Time Clock
TYPICAL OPERATING CHARACTERISTICS (VCC = 3.3v, TA = +25°C, unless otherwise noted.)
IBACKUP vs. VBACKUPVBACKUP (V)
CURRE
VCC=0V
RS1=RS0=1
IBATOSC2
(SQWE = 1)
IBATOSC1
(SQWE = 0)
IBACKUP vs. Temperature
VBACKUP = 3.0VTEMPERATURE (°C)
CURRE
VCC=0V
INTCN = 0
RS2 = RS1 = 1
INTCN = 0
ICC vs. VCCVCC (V)
CURRE
SCL=400kHz
ICCA
SCL=SDA=0Hz
ICCS
Oscillator Frequency vs. Supply VoltageOscillator Supply Voltage (V)
NCY
DS1339 I2C Serial Real-Time Clock
PIN DESCRIPTION
PIN NAME FUNCTION µSOP
SO — X1
Connections for Standard 32.768kHz Quartz Crystal. The internal oscillator
circuitry is designed for operation with a crystal having a specified load
capacitance (CL) of 6pF. An external 32.768kHz oscillator can also drive the
DS1339. In this configuration, the X1 pin is connected to the external oscillator
signal and the X2 pin is left unconnected.
For more information about crystal selection and crystal layout considerations,
refer to Application Note 58: Crystal Considerations with Dallas Real-Time
Clocks. — X2 14 VBACKUP
Secondary Power Supply. Supply voltage must be held between 1.3V and 3.7V
for proper operation. This pin can be connected to a primary cell, such as a
lithium button cell. Additionally, this pin can be connected to a rechargeable cell
or a super cap when used in conjunction with the trickle-charge feature. Diodes
should not be placed in series between the backup source and the VBACKUP input,
or improper operation will result. If a backup supply is not required, VBACKUP must
be grounded. UL recognized to ensure against reverse charging current when
used with a lithium cell. For more information, visit /qa/info/ul. 15 GND Ground. DC power is provided to the device on these pins. 16 SDA
Serial Data Input/Output. SDA is the input/output pin for the I2C serial interface.
The SDA pin is an open-drain output and requires an external pullup resistor.
The pull up voltage may be up to 5.5V regardless of the voltage on VCC. 1 SCL
Serial Clock Input. SCL is used to synchronize data movement on the I2C serial
interface. The pull up voltage may be up to 5.5V regardless of the voltage on
VCC. 2 SQW/INT
Square-Wave/Interrupt Output. Programmable square-wave or interrupt output
signal. The SQW/INT pin is an open-drain output and requires an external pullup
resistor. The pull up voltage may be up to 5.5V regardless of the voltage on VCC.
If not used, this pin may be left unconnected. 3 VCC
Primary Power Supply. When voltage is applied within normal limits, the device
is fully accessible and data can be written and read. When a backup supply is
connected and VCC is below VPF, reads and writes are inhibited. The timekeeping
and alarm functions operate when the device is powered by VCC or VBACKUP. 4–13 N.C. No Connection. These pins are unused and must be connected to ground.
TYPICAL OPERATING CIRCUIT DS1339
CPU
VCC
VCC
VCC12
SDA
SCL
GNDX1
VCC
RPURPU
CRYSTAL
SQW/INT
VBACKUP3
DS1339 I2C Serial Real-Time Clock
DETAILED DESCRIPTION The DS1339 serial real-time clock (RTC) is a low-power clock/date device with two programmable time-of-day
alarms and a programmable square-wave output. Address and data are transferred serially through an I2C bus.
The clock/date provides 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 AM/PM indicator. The DS1339 has a built-in power-
sense circuit that detects power failures and automatically switches to the backup supply, maintaining time, date,
and alarm operation.
OPERATION The DS1339 operates as a slave device on the serial bus. Access is obtained by implementing a START condition
and providing a device identification code followed by data. Subsequent registers can be accessed sequentially
until a STOP condition is executed. The device is fully accessible and data can be written and read when VCC is
greater than VPF. However, when VCC falls below VPF, the internal clock registers are blocked from any access. If
VPF is less than VBACKUP, the device power is switched from VCC to VBACKUP when VCC drops below VPF. If VPF is
greater than VBACKUP, the device power is switched from VCC to VBACKUP when VCC drops below VBACKUP. The
registers are maintained from the VBACKUP source until VCC is returned to nominal levels. The block diagram in
Figure 3 shows the main elements of the serial real-time clock.
POWER CONTROL The power-control function is provided by a precise, temperature-compensated voltage reference and a
comparator circuit that monitors the VCC level. The device is fully accessible and data can be written and read
when VCC is greater than VPF. However, when VCC falls below VPF, the internal clock registers are blocked from any
access. If VPF is less than VBACKUP, the device power is switched from VCC to VBACKUP when VCC drops below VPF. If
VPF is greater than VBACKUP, the device power is switched from VCC to VBACKUP when VCC drops below VBACKUP. The
registers are maintained from the VBACKUP source until VCC is returned to nominal levels (Table 1). After VCC returns
above VPF, read and write access is allowed after tREC (Figure 1). On the first application of power to the device the
time and date registers are reset to 01/01/00 01 00:00:00 (MM/DD/YY DOW HH:MM:SS).
Table 1. Power Control
SUPPLY CONDITION READ/WRITE
ACCESS
POWERED
BY VCC < VPF, VCC < VBACKUP No VBACKUP
VCC < VPF, VCC > VBACKUP No VCC
VCC > VPF, VCC < VBACKUP Yes VCC
VCC > VPF, VCC > VBACKUP Yes VCC
OSCILLATOR CIRCUIT The DS1339 uses an external 32.768kHz crystal. The oscillator circuit does not require any external resistors or
capacitors to operate. Table 2 specifies several crystal parameters for the external crystal. Figure 3 shows a
functional schematic of the oscillator circuit. The startup time is usually less than 1 second when using a crystal
with the specified characteristics.
DS1339 I2C Serial Real-Time Clock
Table 2. Crystal Specifications*
PARAMETER SYMBOL MIN TYP MAX UNITS Nominal Frequency fO 32.768 kHz
Series Resistance ESR 50 kΩ
Load Capacitance CL 6 pF
*The crystal, traces, and crystal input pins should be isolated from RF generating signals. Refer to
Application Note 58: Crystal Considerations for Dallas Real-Time Clocks for additional specifications.
CLOCK ACCURACY The accuracy of the clock is dependent upon the accuracy of the crystal and the accuracy of the match between
the capacitive load of the oscillator circuit and the capacitive load for which the crystal was trimmed. Additional
error is added by crystal frequency drift caused by temperature shifts. External circuit noise coupled into the
oscillator circuit may result in the clock running fast. Figure 4 shows a typical PC board layout for isolating the
crystal and oscillator from noise. Refer to Application Note 58: Crystal Considerations with Dallas Real-Time
Clocks for detailed information
DS1339C ONLY The DS1339C integrates a standard 32,768Hz crystal in the package. Typical accuracy at nominal VCC and +25°C
is approximately 10ppm. Refer to Application Note 58 for information about crystal accuracy vs. temperature.
Figure 4. Typical PC Board Layout for Crystal LOCAL GROUND PLANE (LAYER 2)
CRYSTAL
X1
X2
GND
NOTE: AVOID ROUTING SIGNALS IN
THE CROSSHATCHED AREA (UPPER
LEFT-HAND QUADRANT) OF THE
PACKAGE UNLESS THERE IS A
GROUND PLANE BETWEEN THE
SIGNAL LINE AND THE PACKAGE.
