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DS1340

DS1340, DS1340C

I²C RTC with Trickle Charger

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

Data Sheet
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Overview

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.
DS1340, DS1340C: Typical Operating Circuit DS1340, DS1340C: Typical Operating Circuit Enlarge+

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

Part NumberInterfaceVSUPPLY
(V)		Time Keeping Current
(nA)		CL
(pF)		Memory TypeTime of Day AlarmsIntegrated ResonatorFunctionsPackage/PinsBudgetary
Price
typSee Notes
DS1340 I2C
1.8
3
3.3
5
80012.5None0-RTC
SOIC (N)/8
SOIC (W)/16
UMAX/8
$1.50 @1k
DS1340C XTAL
SOIC(N)/8
$2.75 @1k
See All Timekeeping & Real-Time Clocks (77)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Design Resources

Technical Documents

Tutorial 5791 Tips for Writing Bulletproof Real-Time Clock Control Code
Tutorial 5413 State Machine Logic in Binary-Coded Decimal (BCD)-Formatted Real-Time Clocks
App Note 5383 Adding Intelligence to LED Lighting
Reference Schematic 5320 Intelligent Lighting Controller Measures Ambient Light and Tracks Time
App Note 4427 Demonstrating Green Technology with Apples, Oranges, Lemons, and Limes
App Note 4247 Oscillator Design Considerations for Low-Current Applications
App Note 3816 Selecting a Backup Source for Real-Time Clocks
App Note 3572 FAQ About the Integrated-Crystal Package Option
App Note 3517 Estimating Super Capacitor Backup Time on Trickle-Charger Real-Time Clocks
App Note 701 Using the DS32kHz with Maxim Real-Time Clocks
App Note 505 Lithium Coin-Cell Batteries: Predicting an Application Lifetime
App Note 504 Design Considerations for Maxim Real-Time Clocks
App Note 95 Interfacing the DS1307 with an 8051-Compatible Microcontroller
App Note 82 Using the Dallas Tricklecharge Timekeeper
App Note 58 Crystal Considerations with Maxim Real-Time Clocks (RTCs)

Quality and Environmental Data

Product Reliability Reports: DS1340.pdf 
Request Reliability Report for: DS1340C 
Lead-Free Package Tin (Sn) Whisker Reports

Additional Resources

RTC Calculator
Super Capacitor Calculator

Why on Earth Don’t You Include a Clock in Your Design?


Tools & Models

  • DS1340 IBIS Model

    • CAD Symbols and Footprints

  • DS1340C-18#
  • DS1340C-3#
  • DS1340C-33#
  • DS1340C-33#T&R
  • DS1340U-18+
  • DS1340U-3+
  • DS1340U-3+T&R
  • DS1340U-33+
  • DS1340U-33+T&R
  • DS1340Z-18+
  • DS1340Z-3+
  • DS1340Z-3+T&R
  • DS1340Z-33+
  • DS1340Z-33+T&R
    •

    Quality And Environmental

    Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

    Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

    Quality Management System >
    Environmental Management System >

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    Related Resources

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    Technical Docs

    Events


    Belle Isle 2020
    05/29/2020 - 05/31/2020, Detroit, MI
    2020 Detroit Grand Prix - Chevrolet Detroit Grand Prix presented by Lear Fast Facts The Chevrolet Detroit Grand Prix presented by Lear was hosted on Belle Isle, May 29 - 30 2020. The event featured the cars of the NTT IndyCar Series, the IMSA WeatherTech SportsCar Championship and the Trans Am Series presented by Pirelli. The weekend is collectively referred to as the Chevrolet Detroit Grand Prix presented by Lear and it once again featured the Chevrolet Dual in Detroit IndyCar doubleheader.

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