ENGLISH 简体中文 日本語 한국어  

DS1305
Serial Alarm Real-Time Clock

3-Wire/SPI Serial Interface Trickle Charge Real-Time Clock with Alarms


  QuickView     Technical Documents     Ordering Info     More Information     All  
Data Sheet
FULL DATA SHEET (PDF, 496kB)
Download this datasheet in PDF formatDownload   Send this datasheet to any email addressE-Mail


Description
The DS1305 serial alarm real-time clock provides a full binary coded decimal (BCD) clock calendar that is accessed by a simple serial interface. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. In addition, 96 bytes of NV RAM are provided for data storage. The DS1305 will maintain the time and date, provided the oscillator is enabled, as long as at least one supply is at a valid level. An interface logic power-supply input pin (VCCIF) allows the DS1305 to drive SDO and active-low PF pins to a level that is compatible with the interface logic. This allows an easy interface to 3V logic in mixed supply systems.

The DS1305 offers dual-power supplies as well as a battery input pin. The dual power supplies support a programmable trickle charge circuit that allows a rechargeable energy source (such as a super cap or rechargeable battery) to be used for a backup supply. The VBAT pin allows the device to be backed up by a non-rechargeable battery. The DS1305 is fully operational from 2.0V to 5.5V.

Two programmable time-of-day alarms are provided by the DS1305. Each alarm can generate an interrupt on a programmable combination of seconds, minutes, hours, and day. "Don't care" states can be inserted into one or more fields if it is desired for them to be ignored for the alarm condition. The time-of-day alarms can be programmed to assert two different interrupt outputs or to assert one common interrupt output. Both interrupt outputs operate when the device is powered by VCC1, VCC2, or VBAT.

The DS1305 supports direct serial peripheral interface SPI™ to serial data ports or standard 3-wire interface. A straightforward address and data format is implemented in which data transfers can occur 1 byte at a time or in multiple-byte-Burst Mode®.

Key Features
  • Real-Time Clock (RTC) Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year with Leap-Year Compensation Valid Up to 2100
  • 96-Byte, Battery-Backed NV RAM for Data Storage
  • Two Time-of-Day Alarms, Programmable on Combination of Seconds, Minutes, Hours, and Day of the Week
  • Supports Motorola SPI (Serial Peripheral Interface) Modes 1 and 3 or Standard 3-Wire Interface
  • Burst Mode for Reading/Writing Successive Addresses in Clock/RAM
  • Dual-Power Supply Pins for Primary and Backup Power Supplies
  • Optional Trickle Charge Output to Backup Supply
  • 2.0V to 5.5V Operation
  • Optional industrial Temperature Range: -40°C to +85°C
  • Available in Space-Efficient, 20-Pin TSSOP Package
  • Underwriters Laboratory (UL) Recognized

Key Specifications:   Timekeeping & Real-Time Clocks
Part Number Time Format (hh = sec/100) Date Format Interface Supply Voltage (V) Time- keeping Current (typ) (nA) CL, Load Capacitance (pF) Memory Type Memory Size (Bytes) Number of Time of Day Alarms Features RoHS Available Package Smallest Available Package (max w/pins) (mm2) Operating Temp. Range (°C) Price**
DS1305  HH:MM:SS YY-MM-DD 3-Wire
SPI
2
3
3.3
5
450 6 NV SRAM 96 2
Periodic Interrupt
Power Fail Output
Trickle Charger
Yes PDIP/16
TSSOP/20
45 -40 to +85 $1.84 @ 1k
See All Timekeeping & Real-Time Clocks (86)
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 prices and delivery, please see the price and availability page or contact an authorized distributor.

Diagram
DS1305: Typical Operating Circuit
Typical Operating Circuit

Application Notes
  • Application Note 58: Crystal Considerations with Dallas Real-Time Clocks (RTCs) - DS1305
  • Application Note 502: Interfacing SPI Real-Time Clocks (RTCs) with a Microcontroller - DS1305
  • Application Note 504: Design Considerations for Dallas Semiconductor Real-Time Clocks - DS1305
  • Application Note 505: Lithium Coin-Cell Batteries: Predicting an Application Lifetime - DS1305
  • Application Note 701: Using the DS32kHz with Dallas Real-Time Clocks - DS1305
  • Application Note 2361: Interfacing an SPI-Interface RTC with a PIC Microcontroller - DS1305
  • Application Note 2833: Interfacing an SPI RTC with a Motorola DSP - DS1305
  • Application Note 3510: Interfacing a DS1305 RTC with an 8051-Type Microcontroller - DS1305
  • Application Note 3517: Estimating Super Capacitor Backup Time on Trickle-Charger Real-Time Clocks - DS1305
  • Application Note 3816: Selecting a Backup Source for Real-Time Clocks - DS1305

    Evaluation Kits
    none

    Design Guides
  • REAL-TIME CLOCKS (PDF)

    Reliability Reports
  • Reliability Report: DS1305.pdf

    Software/Models
    none

    Ordering Information
    Notes:

    1. Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
    2. Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
    3. Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: SeeFull Data Sheet or Part Naming Conventions.
    4. * Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.


    Devices: 1-13 of 13

    DS1305 Free
    Sample
    Buy
    Package: TYPE PINS FOOTPRINT
      DRAWING CODE/VAR *
    Temp RoHS/Lead-Free?
    Materials Analysis
    DS1305  
    PDIP;16 pin;158 mm²
    Dwg: 56-G5005-002A (PDF)
    Use pkgcode/variation: P16-1*
    0°C to +70°C RoHS/Lead-Free: No
    Materials Analysis
    DS1305+  
    PDIP;16 pin;158 mm²
    Dwg: 56-G5005-002A (PDF)
    Use pkgcode/variation: P16+1*
    0°C to +70°C RoHS/Lead-Free: Lead Free
    Materials Analysis
    DS1305N+  
    PDIP;16 pin;158 mm²
    Dwg: 56-G5005-002A (PDF)
    Use pkgcode/variation: P16+1*
    -40°C to +85°C RoHS/Lead-Free: Lead Free
    Materials Analysis
    DS1305N  
    PDIP;16 pin;158 mm²
    Dwg: 56-G5005-002A (PDF)
    Use pkgcode/variation: P16-1*
    -40°C to +85°C RoHS/Lead-Free: No
    Materials Analysis
    DS1305EN+T&R/C01  
    TSSOP;20 pin;45 mm²
    Dwg: 56-G2010-000B (PDF)
    Use pkgcode/variation: U20+1*
    -40°C to +85°C RoHS/Lead-Free: Lead Free
    Materials Analysis
    DS1305E/T&R  
    TSSOP;20 pin;45 mm²
    Dwg: 56-G2010-000B (PDF)
    Use pkgcode/variation: U20-1*
    0°C to +70°C RoHS/Lead-Free: No
    Materials Analysis
    DS1305E+T&R  
    TSSOP;20 pin;45 mm²
    Dwg: 56-G2010-000B (PDF)
    Use pkgcode/variation: U20+1*
    0°C to +70°C RoHS/Lead-Free: Lead Free
    Materials Analysis
    DS1305E  
    TSSOP;20 pin;45 mm²
    Dwg: 56-G2010-000B (PDF)
    Use pkgcode/variation: U20-1*
    0°C to +70°C RoHS/Lead-Free: No
    Materials Analysis
    DS1305E+  
    TSSOP;20 pin;45 mm²
    Dwg: 56-G2010-000B (PDF)
    Use pkgcode/variation: U20+1*
    0°C to +70°C RoHS/Lead-Free: Lead Free
    Materials Analysis
    DS1305EN/T&R  
    TSSOP;20 pin;45 mm²
    Dwg: 56-G2010-000B (PDF)
    Use pkgcode/variation: U20-1*
    -40°C to +85°C RoHS/Lead-Free: No
    Materials Analysis
    DS1305EN+  
    TSSOP;20 pin;45 mm²
    Dwg: 56-G2010-000B (PDF)
    Use pkgcode/variation: U20+1*
    -40°C to +85°C RoHS/Lead-Free: Lead Free
    Materials Analysis
    DS1305EN+T&R  
    TSSOP;20 pin;45 mm²
    Dwg: 56-G2010-000B (PDF)
    Use pkgcode/variation: U20+1*
    -40°C to +85°C RoHS/Lead-Free: Lead Free
    Materials Analysis
    DS1305EN  
    TSSOP;20 pin;45 mm²
    Dwg: 56-G2010-000B (PDF)
    Use pkgcode/variation: U20-1*
    -40°C to +85°C RoHS/Lead-Free: No
    Materials Analysis

    More Information
  • RTC Calculator
  • Super Capacitor Calculator

    Related Products
    DS1302 Trickle-Charge Timekeeping Chip
    DS1306 Serial Alarm Real-Time Clock
    MAX6902 SPI-Compatible RTC in a TDFN
    MAX6901 3-Wire Serial RTC in a TDFN
    DS1390, DS1391, DS1392, DS1393 Low-Voltage SPI/3-Wire RTCs with Trickle Charger

    Didn't Find What You Need?
  • Next Day Product Selection Assistance from Applications Engineers
  • Parametric Search
  • Applications Help
  •  QuickView   Technical Documents   Ordering Info   More Information  
     Description 
     Key Features 
     Applications/Uses 
     Key Specifications 
     Diagram 

     Data Sheet 
     Application Notes 
     Design Guides 
     Engineering Journals 
     Reliability Reports 
     Software/Models 
     Evaluation Kits 

     Price and Availability 
     Samples 
     Buy Online 
     Package Information 
     Lead-Free Information 

     Related Products 
     Notes and Comments 
     Evaluation Kits 

    2005-07-08
    This page last modified: 2008-01-23




             


          Privacy Policy    Legal Notices

          Copyright © 2008 by Maxim Integrated Products, Dallas Semiconductor


    ">