DS1218S

Controllers Overview

The DS1218S is a nonvolatile RAM controller IC manufactured by Analog Devices Inc./Maxim Integrated, designed to convert standard CMOS RAM into nonvolatile memory. It operates within a supply voltage range of 4.5V to 5.5V and supports a battery supply of 2.5V to 3.5V. The device functions in an industrial temperature range of 0°C to +70°C and is housed in an 8-SOIC package. Key electrical characteristics include an active current consumption of up to 5 mA, a maximum battery current drain of 100 nA, and a chip enable propagation delay of 10 ns.

Controllers Feature Summary

• Converts CMOS RAM into nonvolatile memory by monitoring incoming power for out-of-tolerance conditions
• Automatically switches to battery backup when a power failure occurs to ensure uninterrupted power
• Unconditionally write protects the memory when the supply voltage is detected as out of tolerance

Controllers Applications

• Battery-backup systems for static RAM
• Nonvolatile memory conversion circuits
• Power-fail detection and protection logic

Controllers Procurement Notes

Verify component authenticity through authorized distributors or manufacturer channels. Confirm RoHS compliance status based on specific ordering suffixes, as lead-free variants exist. Check datasheet revisions for updated thermal and absolute maximum ratings before final integration.

Controllers Selection Notes

Select this controller when integrating external CMOS SRAM requires automatic battery switching and write protection. Ensure the target RAM operates within the specified voltage limits and that the PCB layout accommodates the 8-pin SOIC footprint. Verify that the application environment remains within the 0°C to +70°C operating temperature range.

Controllers Part Context

The DS1218 series belongs to a family of nonvolatile controllers designed to simplify the implementation of battery-backed memory systems. It eliminates the need for complex discrete circuitry by integrating power monitoring, switching, and protection logic into a single compact package.

Controllers Replacement Considerations

DS1218S+