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DS1340, DS1340C
I²C RTC with Trickle Charger
I²C Real-Time Clock with Trickle Charger Offers Software Clock Calibration
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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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Technical Docs
| Data Sheet | I²C RTC with Trickle Charger | Apr 27, 2015 |
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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.
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 SearchOur dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal
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