SLUS900F December   2008  – August 2026

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
    1.     Pin Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings #GUID-4430518C-46E5-4467-8224-12E6F82A6B20/AMR001
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 I2C Timing Requirements
    7. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 IRQ Function
      2. 6.3.2 VBACK Switchover
      3. 6.3.3 Trickle Charge
    4. 6.4 Device Functional Modes
    5. 6.5 Programming
      1. 6.5.1 I2C Serial Interface
  8. 7 Register Maps
    1. 7.1 I2C Read After Backup Mode
    2. 7.2 Normal Register Descriptions
      1. 7.2.1  SECONDS Register (address = 0x00) [reset = 0XXXXXXb]
      2. 7.2.2  MINUTES Register (address = 0x01) [reset = 1XXXXXXb]
      3. 7.2.3  CENT_HOURS Register (address = 0x02) [reset = XXXXXXXXb]
      4. 7.2.4  DAY Register (address = 0x03) [reset = 00000XXXb]
      5. 7.2.5  DATE Register (address = 0x04) [reset = 00XXXXXXb]
      6. 7.2.6  MONTH Register (address = 0x05) [reset = 000XXXXXb]
      7. 7.2.7  YEARS Register (address = 0x06) [reset = XXXXXXXXb]
      8. 7.2.8  CAL_CFG1 Register (address = 0x07) [reset = 10000000b]
      9. 7.2.9  TCH2 Register (address = 0x08) [reset = 10010000b]
      10. 7.2.10 CFG2 Register (address = 0x09) [reset = 10101010b]
    3. 7.3 Special Function Registers
      1. 7.3.1 SF KEY 1 Register (address = 0x20) [reset = 00000000b]
      2. 7.3.2 SF KEY 2 Register (address = 0x21) [reset = 00000000b]
      3. 7.3.3 SFR Register (address = 0x22) [reset = 00000000b]
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Reading From a Register
        2. 8.2.2.2 Leap Year Compensation
        3. 8.2.2.3 Utilizing the Backup Supply
        4. 8.2.2.4 Calibration Example of Crystal Input
        5. 8.2.2.5 Calculating the Super Capacitor Values Example
      3. 8.2.3 Application Curves
    3.     Power Supply Recommendations
    4. 8.3 Layout
      1. 8.3.1 Layout Guidelines
      2. 8.3.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
    2. 9.2 Community Resources
    3. 9.3 Trademarks
  11. 10Revision History
  12.   Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6.4 Device Functional Modes

When the device switches from the main power supply to backup supply, the Time keeping register Registers [0-9] cannot be accessed via the I2C. The access to these registers are only when VCC > Vref.

The Time keeping registers can take up to 1 second to update after the device switches from backup power supply to main power supply.