DS1340, DS1340C:I²C RTC with Trickle Charger

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

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
DS1340, DS1340C: Typical Operating Circuit
DS1340, DS1340C: Typical Operating Circuit
Applications/Uses
  • Medical Equipment
  • Point-of-Sale Equipment
  • Portable Instrumentation
  • Telecommunications
DataSheet
titleDownload file
DS1340-DS1340C Data SheetDS1340-DS1340C.pdf
Parametrics
Part NumberInterfaceVSUPPLY
(V)
Time Keeping Current
(nA)
CL
(pF)
Memory TypeTime of Day AlarmsIntegrated ResonatorFunctionsPackage/PinsBudgetary
Price
typSee Notes
DS1340I2C1.8
3
3.3
5
80012.5None0-RTCµMAX/8
SOIC/16
SOIC(N)/8
$1.50 @1k
DS1340CXTALµMAX/8
SOIC/16
SOIC(N)/8
$2.71 @1k
Quality and Environmental Data
Related Products
  • DS1338:I²C RTC with 56-Byte NV RAM
  • DS1339:I²C Serial Real-Time Clock
  • DS1307:64 x 8, Serial, I²C Real-Time Clock
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1340C-18No Longer AvailableDS1340C-18#SOIC,;16 pin;SOIC;16 pin-40°C to +85°CNo
DS1340C-18#ActiveSOIC,;16 pin;SOIC (;16 pin-40°C to +85°C
DS1340C-3No Longer AvailableDS1340C-3#SOIC,;16 pin;SOIC;16 pin-40°C to +85°CNo
DS1340C-3#ActiveSOIC,;16 pin;SOIC (;16 pin-40°C to +85°C
DS1340C-33No Longer AvailableDS1340C-33#SOIC,;16 pin;SOIC;-40°C to +85°CNo
DS1340C-33#ActiveSOIC,;16 pin;SOIC (;16 pin-40°C to +85°C
DS1340C-33#T&RActiveSOIC,;16 pin;SOIC (;-40°C to +85°C
DS1340U-18No Longer AvailableDS1340U-18+µMAX,;8 pin;15.6 mm²-40°C to +85°CNo
DS1340U-18+ActiveµMAX,;8 pin;15.6 mm²-40°C to +85°CLead Free
DS1340U-3No Longer AvailableDS1340U-3+µMAX,;8 pin;15.6 mm²-40°C to +85°CNo
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1340U-3+ActiveµMAX,;8 pin;15.6 mm²-40°C to +85°CLead Free
DS1340U-3+T&RActiveµMAX,;8 pin;15.6 mm²-40°C to +85°CLead Free
DS1340U-33No Longer AvailableDS1340U-33+µMAX,;8 pin;15.6 mm²-40°C to +85°CNo
DS1340U-33+ActiveµMAX,;8 pin;15.6 mm²-40°C to +85°CLead Free
DS1340U-33+T&RActiveµMAX,;8 pin;15.6 mm²-40°C to +85°CLead Free
DS1340U-33/T&RNo Longer AvailableDS1340U-33+T&RµMAX,;8 pin;15.6 mm²-40°C to +85°CNo
DS1340Z-18No Longer AvailableDS1340Z-18+SOIC(N),;8 pin;30.9 mm²-40°C to +85°CNo
DS1340Z-18+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +85°CLead Free
DS1340Z-3No Longer AvailableDS1340Z-3+SOIC(N),;8 pin;30.9 mm²-40°C to +85°CNo
DS1340Z-3+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +85°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1340Z-3+T&RActiveSOIC(N),;8 pin;30.9 mm²-40°C to +85°CLead Free
DS1340Z-33No Longer AvailableDS1340Z-33+SOIC(N),;8 pin;30.9 mm²-40°C to +85°CNo
DS1340Z-33+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +85°CLead Free
DS1340Z-33+T&RActiveSOIC(N),;8 pin;30.9 mm²-40°C to +85°CLead Free
DS1340Z-33/T&RNo Longer AvailableDS1340Z-33+T&RSOIC(N),;8 pin;30.9 mm²-40°C to +85°CNo
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