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Numéro de sérieDS1340
CategorieTiming Circuits => Real Time Clocks
DescriptionI²C RTC With Trickle Charger
The DS1340 is a real-time clock (RTC)/calendar that is pin compatible and functionally equivalent to the ST M41T00, including the software clock calibration. The device additionally provides trickle-charge capability on the VBACKUP pin, a lower timekeeping voltage, and an oscillator STOP flag. Block access of the register map is identical to the ST device. Two additional registers, which are accessed individually, are required for the trickle charger and flag. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. A built-in power-sense circuit detects power failures and automatically switches to the backup supply. The device is programmed serially through an I²C bidirectional bus.
SociétéMaxim Integrated Products
DatasheetTélécharger DS1340 datasheet
 
 
  • Description courte

  • The is a real-time clock (RTC)/calendar that is pin compatible and functionally equivalent to the ST M41T00, including the software clock calibration. The device additionally provides trickle-charge capability on the VBACKUP pin, a lower timekeeping voltage, and an oscillator STOP flag. Block access of the register map is identical to the ST device. Two additional registers, which are accessed individually, are required for the trickle charger and flag. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. A built-in power-sense circuit detects power failures and automatically switches to the backup supply. Reads and writes are inhibited while the clock continues to run. The device is programmed serially through an I2C bidirectional bus.

    Features

    Enhanced Second Source for the ST M41T00 Available in a Surface-Mount Package with an Integrated Crystal (DS1340C) Fast (400kHz) I2C 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 Laboratories (UL) Recognized

    Applications
    Portable Instruments Point-of-Sale Equipment Medical Equipment Telecommunications

    + Denotes a lead-free/RoHS-compliant device. # 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 leadfree soldering processes. A anywhere on the top mark denotes a lead-free device. A denotes a RoHS-compliant device.

    For pricing, delivery, and ordering information, please contact Maxim Direct 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.

    Voltage Range on VCC Pin Relative to +6.0V Voltage Range on SDA, SCL, and FT/OUT Relative Ground..................................-0.3V to (VCC + 0.3V) Operating Temperature to +85°C Storage Temperature 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.

    (VCC = VCC MIN to VCC MAX, to +85°C, unless otherwise noted.) (Note 1, Figure 1)

    PARAMETER SCL Clock Frequency Bus Free Time Between STOP and START Conditions Hold Time (Repeated) START Condition (Note 2) Low Period of SCL Clock High Period of SCL Clock Data Hold Time (Notes 3, 4) Data Setup Time (Note 5) START Setup Time Rise Time of SDA and SCL Signals (Note 6) Fall Time of SDA and SCL Signals (Note 6) Setup Time for STOP Condition Capacitive Load for Each Bus Line I/O Capacitance (SCL, SDA) Pulse Width of Spikes that Must be Suppressed by the Input Filter Oscillator Stop Flag (OSF) Delay SYMBOL fSCL tBUF tHD:STA tLOW tHIGH tHD:DAT tSU:DAT tSU:STA tR tF tSU:STO CB CI/O tSP tOSF Fast mode (Note 7) CONDITIONS Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode (Note MIN + 0.1CB TYP MAX 100 400 UNITS kHz ns ms

    (VCC = VCC MIN to VCC MAX, to +85°C, unless otherwise noted. Typical values are at VCC = +25°C, unless otherwise noted.) (Note 1)

    PARAMETER Supply Voltage (Note 8) Input Logic 1 (SDA, SCL) Input Logic 0 (SDA, SCL) Supply Voltage, Pullup (FT/OUT, SDA, SCL), VCC = 0V Backup Supply Voltage (Note 8) SYMBOL DS1340-18 VCC VIH VIL VPU DS1340-3 DS1340-33 (Note 8) (Note 8) (Note 8) DS1340-18 VBACKUP R1 Trickle-Charge Current-Limiting Resistors R2 R3 Power-Fail Voltage (Note 8) Input Leakage (SCL, CLK) I/O Leakage (SDA, FT/OUT) SDA Logic 0 Output VPF ILI ILO IOLSDA VCC > 2V; VOL 1.7V < VCC < 2V; VOL 0.2 x VCC > 2V; VOL = 0.4V FT/OUT Logic 0 Output IOLSQW 1.7V < VCC < 2V; VOL 0.2 x VCC 1.3V < VCC < 1.7V; VOL = 0.2x VCC DS1340-18 Active Supply Current (Note 13) ICCA DS1340-33 DS1340-18 Standby Current (Note 14) VBACKUP Leakage Current ICCS DS1340-3 DS1340-33 IBACKUPLKG VBACKUP DS1340-3 DS1340-33 (Notes 9, 10) (Note 11) (Note µA V CONDITIONS MIN x VCC -0.3 TYP 3.0 3.3 MAX 3.3 5.5 VCC 0.3 x VCC UNITS V

    (VCC = 0V, VBACKUP to +85°C, unless otherwise noted.) (Note 1)

    PARAMETER SYMBOL IBACKUP2 IBACKUP3 VBACKUP Data-Retention Current CONDITIONS OSC ON, = 0 (Note 15) OSC ON, = 1 (Note 15) OSC ON, = 0, VBACKUP = +25°C (Notes 15, 16) MIN TYP MAX nA UNITS