DS1211S

Controllers Overview

The DS1211S+ is a nonvolatile memory 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 an integrated 3-to-8 decoder that provides control for up to eight CMOS RAM chips. It includes automatic switching to battery power upon power-fail detection and unconditionally write protects data when VCC is out of tolerance. The component is available in a 20-pin SOIC surface-mount package.

Controllers Feature Summary

• Converts standard CMOS RAMs into nonvolatile memories by monitoring incoming power for out-of-tolerance conditions
• Integrates a 3-to-8 decoder providing independent chip enable outputs for controlling up to eight separate CMOS RAM devices
• Automatically switches to battery backup and inhibits chip enables to achieve unconditional write protection during power failures
• Tests battery condition on power-up and supports redundant battery configurations

Controllers Applications

• Data logging systems requiring persistent storage
• Real-time clock applications with calendar and timekeeping functions
• Embedded controllers needing configuration parameter retention
• Industrial equipment requiring fault-safe memory states

Controllers Procurement Notes

Verify the specific suffix against official documentation, as ordering codes may indicate variations in temperature range or packaging. Confirm RoHS compliance status prior to integration. Check manufacturer lifecycle notices for obsolescence warnings. Ensure the selected variant matches the required PCB footprint and thermal specifications for the target environment.

Controllers Selection Notes

Select this controller when designing systems that utilize multiple CMOS SRAMs requiring unified nonvolatile management. The integrated decoding logic simplifies board layout by reducing external gate requirements. Consider the low standby current for battery-powered designs. Verify that the host processor can interface correctly with the provided address and control signals.

Controllers Part Context

The DS1211 belongs to a family of nonvolatile controllers manufactured by Analog Devices / Maxim Integrated. It serves as a companion to various CMOS RAM devices to create complete nonvolatile memory solutions. The series addresses the common application problem of preserving data during power interruptions without requiring complex external circuitry.

Controllers Replacement Considerations

Public confirmed substitute part numbers are not available in the provided source material.