User Manual

ManualsBrandsRainbow Electronics ManualsComputer HardwareDS1339

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Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device

may be simultaneously available through various sales channels. For information about device errata, click here: http://www.maxim-ic.com/errata.

FEATURES

§ Real-time clock (RTC) counts seconds,

minutes, hours, day, date, month, and year

with leap-year compensation valid up to 2100

§ 2-wire serial interface

§ Two time-of-day alarms

§ Programmable square-wave output

§ Oscillator stop flag

§ Automatic power-fail detect and switch

circuitry

§ Trickle charge capability

ORDERING INFORMATION

PART

PIN-

PACKAGE

TOP MARK

DS1339U-2 8 µSOP 1339 ##-2

DS1339U-3 8 µSOP 1339 ##-3

DS1339U-33 8 µSOP 1339 ##-33

## = second line, revision code

2 = 2.0V, V

±10%

3 = 3.0V, V

±10%

33 = 3.3V, V

±10%

PIN ASSIGNMENT (Top View)

Package Dimension Information

http://www.maxim-ic.com/TechSupport/DallasPackInfo.htm

PIN DESCRIPTION

- Power Supply

X1, X2 - 32.768kHz Crystal Connection

GND - Ground

SDA - Serial Data

SCL - Serial Clock

BACKUP

- Secondary Power Supply

SQW/ INT - Square-Wave/Interrupt Output

APPLICATIONS

§ Handhelds (GPS, POS Terminal)

§ Consumer Electronics (Set-Top Box, Digital

Recording, Network Appliance)

§ Office Equipment (Fax/Printer, Copier)

§ Medical (Glucometer, Medicine Dispenser)

§ Telecommunications (Router, Switcher,

Server)

§ Other (Utility Meter, Vending Machine,

Thermostat, Modem)

DS1339

Serial Real-Time Clock

www.maxim-ic.com

DS1339

CPU

VCC

SDA

SCL

GND

X2X1

VCC

RPU RPU

CRYSTAL

SQW /INT

VBACKUP

TYPICAL OPERATING CIRCUIT

8-Pin mSOP

SQW/

GND

SCL

SDA

BACKUP

Summary of content (18 pages)

PAGE 1
DS1339 Serial Real-Time Clock www.maxim-ic.com www.maxim-ic.
PAGE 2
DS1339 DESCRIPTION The DS1339 serial real-time clock 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 by a 2-wire bidirectional 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.
PAGE 3
DS1339 SIGNAL DESCRIPTIONS VCC, GND – DC power is provided to the device on these pins. SCL (Serial Clock Input) – SCL is used to synchronize data movement on the serial interface. SDA (Serial Data Input/Output) – SDA is the input/output pin for the 2-wire serial interface. The SDA pin is an open-drain output and requires an external pullup resistor. VBACKUP (Secondary Supply Input) – Connection for a secondary power supply. Supply voltage must be held between 1.3V and 3.7V for proper operation.
PAGE 4
DS1339 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 can result in the clock running fast.
PAGE 5
DS1339 Figure 2.
PAGE 6
DS1339 TIME AND DATE OPERATION The time and date information is obtained by reading the appropriate register bytes. The real-time clock registers are illustrated in Figure 2. The time and date are set or initialized by writing the appropriate register bytes. The contents of the time and date registers are in the binary coded decimal (BCD) format. The DS1339 can be run in either 12-hour or 24-hour mode. Bit 6 of the hours register is defined as the 12-hour or 24-hour mode-select bit.
PAGE 7
DS1339 Figure 3.
PAGE 8
DS1339 Figure 4. SQUARE-WAVE OUTPUT FREQUENCY RS2 RS1 0 0 1 1 0 1 0 1 SQUARE-WAVE OUTPUT FREQUENCY 1Hz 4.096kHz 8.192kHz 32.768kHz INTCN (Interrupt Control) – This bit controls the relationship between the two alarms and the interrupt output pins. When the INTCN bit is set to logic 1, a match between the timekeeping registers and the Alarm 1 or Alarm 2 registers activate the SQW/ INT pin (provided that the alarms are enabled).
PAGE 9
DS1339 is cleared when written to logic 0. This bit can only be written to logic 0. Attempting to write to logic 1 leaves the value unchanged. A2F (Alarm 2 Flag) – A logic 1 in the A2F bit indicates that the time matched the Alarm 2 registers. If the A2IE bit is a logic 1 and the INTCN bit is set to a logic 1, the SQW/ INT pin is also asserted. A2F is cleared when written to logic 0. This bit can only be written to logic 0. Attempting to write to logic 1 leaves the value unchanged.
PAGE 10
DS1339 Figure 6.
PAGE 11
DS1339 2-WIRE SERIAL DATA BUS The DS1339 supports a bidirectional 2-wire bus and data transmission protocol. A device that sends data onto the bus is defined as a transmitter and a device receiving data as a receiver. The device that controls the message is called a master. The devices that are controlled by the master are referred to as slaves. The bus must be controlled by a master device that generates the serial clock (SCL), controls the bus access, and generates the START and STOP conditions.
PAGE 12
DS1339 Figure 7. DATA TRANSFER ON 2-WIRE SERIAL BUS Depending upon the state of the R/ W bit, two types of data transfer are possible: 1) Data Transfer from a Master Transmitter to a Slave Receiver. The first byte transmitted by the master is the slave address. Next follows a number of data bytes. The slave returns an acknowledge bit after each received byte. Data is transferred with the most significant bit (MSB) first. 2) Data Transfer from a Slave Transmitter to a Master Receiver.
PAGE 13
DS1339 The DS1339 can operate in the following two modes: 1) Slave Receiver Mode (Write Mode): Serial data and clock are received through SDA and SCL. After each byte is received an acknowledge bit is transmitted. START and STOP conditions are recognized as the beginning and end of a serial transfer. Address recognition is performed by hardware after reception of the slave address and direction bit (Figure 8).
PAGE 14
DS1339 ABSOLUTE MAXIMUM RATINGS* Voltage Range on Any Pin Relative to Ground Operating Temperature Range Storage Temperature Range Soldering Temperature Range -0.3V to +6.0V -40°C to +85°C -55°C to +125°C See IPC/JEDEC J-STD-020A *This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operation sections of this specification is not implied.
PAGE 15
DS1339 CRYSTAL SPECIFICATIONS* PARAMETER Nominal Frequency Series Resistance Load Capacitance SYMBOL FO ESR CL MIN TYP 32.768 MAX 45 6 UNITS kHz kΩ pF NOTES *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.
PAGE 16
DS1339 AC ELECTRICAL CHARACTERISTICS (VCC = MIN to MAX, TA = -40°C to +85°C) (Note 12) PARAMETER SCL Clock Frequency Bus Free Time Between a STOP and START Condition Hold Time (Repeated) START Condition SYMBOL fSCL MIN Fast Mode 100 TYP MAX 400 Standard Mode 100 Fast Mode tHD:STA tLOW HIGH Period of SCL Clock tHIGH Setup Time for a Repeated START Condition tSU:STA Data Hold Time tHD:DAT Data Setup Time tSU:DAT Fall Time of Both SDA and SCL Signals tF Setup Time for STOP Condition tSU
PAGE 17
DS1339 Figure 10. TIMING DIAGRAM Figure 11.
PAGE 18
DS1339 POWER-UP DOWN CHARACTERISTICS PARAMETER SYMBOL (TA = -40°C to +85°C) (Note 12) MIN TYP MAX UNITS NOTES 2 ms 13 Recovery at Power-up tREC VCC Fall Time; VPF(MAX) to VPF(MIN) tVCCF 300 ms VCC Rise Time; VPF(MIN) to VPF(MAX) tVCCR 0 ms Warning: Under no circumstances are negative undershoots, of any amplitude, allowed when the device is in backup-battery mode. NOTES: 1) 2) 3) 4) 5) 6) SCL only. SDA, and SQW/ INT . ICCA: SCL at fSC max, VIL = 0.