DS12R885S-5+

Real Time Clock Overview

The DS12R885S-5+ is a real-time clock (RTC) and calendar integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It serves as a functional drop-in replacement for the DS12885, providing timekeeping with leap-year compensation up to the year 2100. The device features 114 bytes of battery-backed static RAM and supports both Intel and Motorola multiplexed bus interfaces. It operates within a supply voltage range of 4.5V to 5.5V and includes an integrated constant-voltage trickle charger for external rechargeable batteries or super capacitors connected to the VBACKUP pin.

Real Time Clock Feature Summary

• Integrated constant-voltage trickle charger supporting rechargeable batteries or super capacitors
• Multiplexed byte-wide interface compatible with Intel and Motorola bus timing modes
• Automatic power-fail detection and switching circuitry between primary and backup supplies
• Leap-year compensation logic valid through the year 2100

Real Time Clock Applications

• Embedded systems requiring precise timekeeping
• Utility meters for data logging and timestamping
• Security systems needing event recording
• Network hubs, bridges, and routers

Real Time Clock Procurement Notes

Verify that the specific ordering suffix '-5+' corresponds to the +5.0V operating voltage variant (-5) and lead-free/RoHS compliance (+). Confirm the package type matches the required 24-SOIC form factor. Ensure the design accommodates the external crystal connection on pins X1 and X2, as this specific part does not integrate the oscillator components found in the DS12CR887 or DS12R887 variants.

Real Time Clock Selection Notes

Select the DS12R885S-5+ when a standard 5V logic interface is required alongside nonvolatile memory storage. This model requires an external 32.768kHz quartz crystal with a 12.5pF load capacitance. For applications necessitating an integrated battery and crystal solution, consider the DS12CR887 or DS12R887 series instead. Ensure the host system can support the multiplexed address/data bus timing requirements for either Intel or Motorola modes via the MOT pin configuration.

Real Time Clock Part Context

This component belongs to the DS12R885/DS12CR887/DS12R887 family of RTCs featuring constant-voltage trickle chargers. The 'S' designation indicates the SOIC surface-mount package, while '-5' specifies the 5V operation range. The '+' suffix denotes lead-free manufacturing compliant with RoHS standards. It is distinct from the DS12885 by its enhanced power management and trickle charging capabilities.

Real Time Clock Replacement Considerations

The DS12R885 is explicitly documented as a functional drop-in replacement for the DS12885. When substituting older DS12885 units, verify that the application circuit supports the integrated trickle charger on the VBACKUP pin, which may require adjustment if using non-rechargeable backup sources.