Date Format
:
Packaging
:
Time Format
: HH:MM:SS
Supply Voltage - Min
: 3 V
Mounting Style
: Through Hole
Maximum Operating Temperature
: + 70 C
Minimum Operating Temperature
: 0 C
RTC Bus Interface
: Multiplexed
Package / Case
: PDIP-28
RTC Memory Size
: 114 B
Function
: Clock, Calendar, NV SRAM Control, Alarm
Supply Voltage - Max
: 5 V
Features: · +3V or +5V Operation
· 64-Bit Silicon Serial Number
· 64-Bit Customer Specific ROM or Additional Serial Number Available
· Power Control Circuitry Supports System Power-On from Date/Time Alarm or Key Closure
· Automatic Battery Backup and Write Protection to External SRAM
· Crystal Select Bit Allows RTC to Operate with 6Pf or 12.5Pf Crystal
· 114 Bytes User NV RAM
· Auxiliary Battery Input
· RAM Clear Input
· Century Register
· 32kHz Output for Power Management
· 32-Bit VCC Powered Elapsed Time Counter
· 32-Bit VBAT Powered Elapsed Time Counter
· 16-Bit Power-Cycle Counter
· Compatible with Existing BIOS for Original DS1287 Functions
· Available as IC (DS1688) or Stand-Alone Module with Embedded Battery and Crystal (DS1691)
· Timekeeping Algorithm Includes Leap Year Compensation Valid Up to 2100Pinout
DescriptionThe DS1688/DS1691 are real-time clocks (RTCs) designed as successors to the industry standard DS1285, DS1385, DS1485, and DS1585 PC real-time clocks. These devices provide the industry standard DS1285 clock function with the new feature of either +3.0V or +5.0V operation and automatic backup and write protection to an external SRAM. The DS1688 also incorporates a number of enhanced features including a silicon serial number, power-on/off control circuitry, 114 bytes of user NV SRAM, power-on elapsed timer, and power-cycle counter.
DS1688 Data Sheet
