DS1321S

Controllers Overview

The DS1321S+ is a flexible nonvolatile controller with a lithium battery monitor, designed to convert CMOS SRAMs into nonvolatile memory. It operates within an industrial temperature range of -40°C to +85°C and accepts a supply voltage between 4.75V and 5.5V. The device supports up to four SRAMs in three configurable modes: four banks of one, two banks of two, or one bank of four. It features automatic power-fail detection, write protection, processor reset generation, and periodic battery monitoring via an open-drain warning output.

Controllers Feature Summary

• Converts standard CMOS SRAMs into nonvolatile memory by managing power switching between main supply and backup battery
• Provides flexible memory organization supporting multiple configurations of attached SRAM devices
• Monitors lithium battery capacity and signals low-battery conditions through an active-low warning output
• Ensures data integrity by unconditionally write-protecting SRAM during power failures and holding the processor in reset

Controllers Applications

• Battery-backed nonvolatile memory systems for embedded controllers
• Industrial equipment requiring reliable data retention during power interruptions
• Telecommunications infrastructure utilizing lithium cell backup for critical storage

Controllers Procurement Notes

Verify that the specific ordering suffix matches the required package type, as the base part number covers multiple physical formats. Confirm RoHS compliance status if lead-free components are mandatory for the assembly process. Ensure the selected variant aligns with the intended operating temperature range and voltage requirements for the target application environment.

Controllers Selection Notes

Select this component when designing systems that require seamless transition from main power to battery backup without data loss. Consider the available memory configurations to determine if the single-chip solution meets the address and chip-enable requirements. Evaluate the battery monitoring needs to ensure the periodic testing interval aligns with system uptime expectations.

Controllers Part Context

This device belongs to the DS1321 family of flexible nonvolatile controllers manufactured by Analog Devices Inc./Maxim Integrated. The family includes variants such as the DS1321S+ (16-pin SO) and DS1321E+ (20-pin TSSOP), all sharing identical functional specifications but differing in physical package dimensions and pinout arrangements for surface-mount integration.

Controllers Replacement Considerations

DS1321S+