Overview
Features and Benefits
- Trickle-Charge Capability for a Rechargeable Battery or Super Cap
- Selectable Intel or Motorola Bus Timing
- RTC Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap-Year Compensation to 2100
- Interrupt Output with Three Independently Maskable Interrupt Flags
- Time-of-Day Alarm is Once-per-Second to Once-per-Day
- Periodic Rates from 122µs to 500ms
- End-of-Clock Update Cycle Flag
- 14 Bytes of Clock and Control Registers
- 114 Bytes of General-Purpose Battery-Backed NV RAM with Clear Input
- Programmable Square-Wave Output
- Automatic Power-Fail Detect and Switch Circuitry
- +5.0V or +3.3V Operation
- Industrial Temperature Range
- DS12CR887 Encapsulated DIP (EDIP) Module with Integrated Battery and Crystal
- DS12R887 BGA Module Surface-Mountable Package with Integrated Crystal and Rechargeable Battery
Product Details
The DS12R885 is a functional drop-in replacement for the DS12885 real-time clock (RTC). The device provides an RTC/calendar, one time-of-day alarm, three maskable interrupts with a common interrupt output, a programmable square wave, and 114 bytes of battery-backed static RAM. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including correction for leap years. It also operates in either 24-hour or 12-hour format with an AM/PM indicator. A precision temperature-compensated circuit monitors the status of VCC. If a primary power failure is detected, the device automatically switches to a backup supply. The VBACKUP pin supports a rechargeable battery or a super cap and includes an integrated, always enabled trickle charger. The DS12R885 is accessed through a multiplexed byte-wide interface, which supports both Intel and Motorola modes. The DS12CR887 and DS12R887 integrate the DS12R885 die with a crystal and battery.
Applications
- Embedded Systems
- Network Hubs, Switches, Routers
- Security Systems
- Utility Meters
Product Categories
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Documentation & Resources
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DS12R885 Reliability Data1/12/2023PDF11K
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Oscillator Design Considerations for Low-Current Applications1/26/2011
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Selecting a Backup Source for Real-Time Clocks5/26/2006
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Calculating ML Cell Life for an RTC Backup Operation3/23/2006
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Problems and Solutions for Adjusting to Changes in Daylight Saving Time3/23/2006
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Interface a Multiplexed-Bus Real-Time Clock to a µP With Separate Address and Data Buses7/17/2002
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Using the DS32kHz with Maxim Real-Time Clocks2/15/2002
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Design Considerations for Maxim Real-Time Clocks2/15/2002
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Crystal Considerations with Maxim Real-Time Clocks (RTCs)3/29/2001
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
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