DS1211

Controllers Overview

The DS1211 is a nonvolatile controller designed to convert full CMOS RAMs into nonvolatile memories. It operates with a supply voltage range of 4.75V to 5.5V and consumes less than 100 nA of battery current. The device features a 3-to-8 decoder providing control for up to eight CMOS RAMs. It includes power-fail detection options of 5% or 10%, redundant battery support, and a power-fail signal for processor interruption. Available in 20-pin DIP and SOIC packages, it supports commercial (0°C to +70°C) and industrial (-40°C to +85°C) temperature ranges.

Controllers Feature Summary

• Converts full CMOS RAMs into nonvolatile memories by monitoring incoming power and inhibiting chip enables when out of tolerance.
• Automatically switches to battery backup upon power failure to supply RAMs with uninterrupted power.
• Features a 3-to-8 decoder that provides control for up to eight CMOS RAMs.

Controllers Applications

• Converting standard CMOS RAMs into nonvolatile memory systems
• Battery-backed memory applications requiring low standby current
• Systems utilizing redundant battery configurations

Controllers Procurement Notes

Verify the specific package variant required, as the DS1211 family includes both through-hole DIP and surface-mount SOIC options. Confirm the operating temperature range matches the application environment, distinguishing between commercial and industrial grades. Check for obsolete status and lead times due to discontinuation. Ensure compatibility with the target CMOS RAM address and data lines before procurement.

Controllers Selection Notes

Select the DS1211 when designing systems that require converting volatile CMOS RAMs into nonvolatile storage without complex interface logic. Choose the industrial temperature grade if operation below 0°C is necessary. Consider the 3-to-8 decoder capability when managing multiple memory chips. Verify that the 5% or 10% power-fail detection threshold aligns with system voltage stability requirements.

Controllers Part Context

The DS1211 belongs to the Dallas Semiconductor/Maxim Integrated nonvolatile controller family, specifically designed to manage battery-backed memory arrays. It serves as a companion to various CMOS SRAMs, simplifying the design of nonvolatile storage solutions. The device integrates decoding logic and power management functions to ensure data integrity during power transitions.

Controllers Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. The component is listed as obsolete. Designers should evaluate newer nonvolatile memory technologies or compatible controllers from the manufacturer's current portfolio for long-term supply assurance.

Controllers FAQ

How does the DS1211 protect data during a power failure?

The DS1211 monitors the VCC supply for out-of-tolerance conditions. When a power failure is detected, it inhibits all chip enables to prevent writes and automatically switches to the connected battery to provide uninterrupted power to the RAMs.

What is the maximum number of CMOS RAMs the DS1211 can control?

The DS1211 contains a 3-to-8 decoder that provides control for up to eight separate CMOS RAM chips.