STK22C48-SF45TR

Memory IC Overview

The STK22C48 is a 16-Kbit (2 K × 8) AutoStore nvSRAM manufactured by Cypress Semiconductor. It integrates SRAM with QuantumTrap nonvolatile elements for data retention. The device supports 25 ns and 45 ns access times, operates on a single 5 V supply (+10%), and features automatic STORE on power-down using an external capacitor. It offers unlimited read/write cycles, 1,000,000 STORE cycles to nonvolatile memory, and 100-year data retention. Available in 28-pin SOIC packages for commercial and industrial temperature ranges.

Memory IC Feature Summary

• Integrates fast static RAM with QuantumTrap nonvolatile cells for parallel data storage and recall.
• Enables hands-off automatic data preservation during power loss via an external capacitor connected to the VCAP pin.
• Supports multiple STORE initiation methods including software commands, hardware signals via the HSB pin, and automatic power-down detection.
• Provides hardware protection against inadvertent writes and STORE operations during low voltage conditions.

Memory IC Applications

• Data logging systems requiring frequent updates with long-term retention
• Industrial control applications needing configuration parameter storage
• Embedded systems requiring non-volatile state preservation across power cycles

Memory IC Procurement Notes

Verify component authenticity as this part is not recommended for new designs and is produced solely for ongoing programs. Confirm package dimensions match specific system requirements, noting variations between 300 mil and 330 mil SOIC footprints. Ensure design includes appropriate bypass capacitors and adheres to specified VCAP sizing guidelines to maintain reliability and prevent internal pass transistor stress.

Memory IC Selection Notes

Select based on required access speed, choosing between 25 ns or 45 ns variants. Determine operating environment to specify Commercial (0°C to +70°C) or Industrial (-40°C to +85°C) temperature grades. Verify PCB layout capabilities for 28-pin SOIC packages and ensure power supply stability meets the 4.5 V to 5.5 V range. Consider system power management strategies regarding VCAP capacitor integration for AutoStore functionality.

Memory IC Part Context

This component belongs to the AutoStore nvSRAM family utilizing Cypress's QuantumTrap technology. It bridges the performance gap between volatile SRAM and slower nonvolatile memories like Flash. Designed for high-cycle endurance applications, it eliminates the need for battery backup while providing SRAM-like speeds. The product line focuses on reliable data retention without complex write-erase cycles associated with traditional EEPROM or Flash technologies.

Memory IC Replacement Considerations

STK22C48-NF25ITR

Memory IC FAQ

How does the AutoStore function operate during power failure?

During normal operation, the device charges a capacitor on the VCAP pin. If VCC drops below the switch threshold, the chip disconnects VCAP from VCC and uses the stored charge to automatically initiate a STORE operation, transferring SRAM data to the nonvolatile QuantumTrap cells.

What is the purpose of the HSB pin?

The Hardware Store Busy (HSB) pin allows external initiation of a STORE cycle when driven LOW. It also serves as an open-drain output that goes LOW to indicate the device is busy performing a STORE operation, preventing other operations until it returns HIGH.

Can the AutoStore feature be disabled?

Yes, by entering AutoStore Inhibit mode. This is achieved by tying VCC to ground and applying +5 V to the VCAP pin. In this configuration, STORE operations are only triggered explicitly via the HSB pin or software sequences.