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I²C RTC with Trickle Charger

I²C Real-Time Clock with Trickle Charger Offers Software Clock Calibration

Product Details

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.

Key Features

  • Enhanced Second Source for the ST M41T00
  • Completely Manages All Timekeeping Functions
    • RTC Counts Seconds, Minutes, Hours, Day, Date, Month, and Year
    • Software Clock Calibration
    • Oscillator Stop Flag
  • Low-Power Operation Extends Battery Backup Run Time
    • Low Timekeeping Voltage Down to 1.3V
    • Automatic Power-Fail Detect and Switch Circuitry
    • Trickle-Charge Capability
  • Three Operating Voltage Ranges (1.8V, 3V, and 3.3V) Supports Systems Using Legacy and Modern Power Buses
  • Surface-Mount Package with an Integrated Crystal (DS1340C) Saves Additional Space and Simplifies Design
  • Simple Serial Port Interfaces with Most Microcontrollers
    • Fast (400kHz) I2C Interface
  • 8-Pin µSOP or SO Package Minimizes Required Space
  • Underwriters Laboratories (UL®) Recognized

Applications/Uses

  • Medical Equipment
  • Point-of-Sale Equipment
  • Portable Instrumentation
  • Telecommunications
Parametric specs for Timekeeping & Real-Time Clocks
Interface I2C
VSUPPLY (V) 3
5
Date/ Time Format (hh = sec/100) YY-MM-DD/ HH:MM:SS
Time Keeping Current (nA) (typ) 800
CL (pF) 12.5
Memory Type None
Time of Day Alarms 0
Integrated Resonator -
Package/Pins SOIC (N)/8
SOIC (W)/16
UMAX/8
Budgetary
Price (See Notes)
$1.58 @1k
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Simplified Block Diagram

DS1340, DS1340C: Typical Operating Circuit DS1340, DS1340C: Typical Operating Circuit Zoom icon

Technical Docs

Data Sheet I²C RTC with Trickle Charger Apr 27, 2015

Design & Development

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SIMULATION MODELS

DS1340 IBIS Model

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Parameters

Parametric specs for Timekeeping & Real-Time Clocks
Interface I2C
VSUPPLY (V) 3
5
Date/ Time Format (hh = sec/100) YY-MM-DD/ HH:MM:SS
Time Keeping Current (nA) (typ) 800
CL (pF) 12.5
Memory Type None
Time of Day Alarms 0
Integrated Resonator -
Package/Pins SOIC (N)/8
SOIC (W)/16
UMAX/8
Budgetary
Price (See Notes)
$1.58 @1k

Key Features

  • Enhanced Second Source for the ST M41T00
  • Completely Manages All Timekeeping Functions
    • RTC Counts Seconds, Minutes, Hours, Day, Date, Month, and Year
    • Software Clock Calibration
    • Oscillator Stop Flag
  • Low-Power Operation Extends Battery Backup Run Time
    • Low Timekeeping Voltage Down to 1.3V
    • Automatic Power-Fail Detect and Switch Circuitry
    • Trickle-Charge Capability
  • Three Operating Voltage Ranges (1.8V, 3V, and 3.3V) Supports Systems Using Legacy and Modern Power Buses
  • Surface-Mount Package with an Integrated Crystal (DS1340C) Saves Additional Space and Simplifies Design
  • Simple Serial Port Interfaces with Most Microcontrollers
    • Fast (400kHz) I2C Interface
  • 8-Pin µSOP or SO Package Minimizes Required Space
  • Underwriters Laboratories (UL®) Recognized

Applications/Uses

  • Medical Equipment
  • Point-of-Sale Equipment
  • Portable Instrumentation
  • Telecommunications

Description

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.

Simplified Block Diagram

DS1340, DS1340C: Typical Operating Circuit DS1340, DS1340C: Typical Operating Circuit Zoom icon

Technical Docs

Data Sheet I²C RTC with Trickle Charger Apr 27, 2015

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal