Infineon Technologies STK22C48-SF25ITR

Overview

STK22C48-SF25ITR from Cypress Semiconductor is a 16-Kbit (2 K × 8) nonvolatile SRAM with AutoStore™ functionality, integrating QuantumTrap™ nonvolatile elements in each memory cell. It operates at 5 V ±10%, delivers 25 ns access time, supports unlimited SRAM read/write cycles, and guarantees 1,000,000 STORE cycles and 100-year data retention - deployed in industrial control systems requiring persistent memory during unexpected power loss.

For engineers reviewing the STK22C48-SF25ITR datasheet, STK22C48-SF25ITR pinout, STK22C48-SF25ITR application, or STK22C48-SF25ITR equivalent, key selection criteria include AutoStore timing behavior, HSB-controlled hardware STORE latency, VCAP capacitor sizing (68 µF), SRAM-to-QuantumTrap transfer reliability, and compatibility with 28-pin SOIC footprint in legacy industrial designs.

Technical Context

The STK22C48-SF25ITR implements a dual-cell architecture: a standard fast SRAM array (32 × 512) paired with parallel QuantumTrap nonvolatile storage (32 × 512). STORE transfers data from SRAM to QuantumTrap on power-down (AutoStore), via HSB assertion, or software command; RECALL restores data on power-up or via software.

It uses a dedicated VCAP pin for energy storage (68–220 µF capacitor), initiates STORE only after at least one write since last STORE/RECALL, and inhibits all external STORE/Write operations when VCC falls below VSWITCH (typically ~3.6 V), ensuring data integrity during brown-out conditions.

Key Specifications

Pinout & Package

STK22C48-SF25ITR is housed in a 28-pin 300-mil Small Outline Integrated Circuit (SOIC) package with gull-wing leads, RoHS-compliant, and rated for industrial temperature operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar nonvolatile SRAM applications.

Compared with CY14B101PA-SXIT and FM24CL64-G, STK22C48-SF25ITR offers direct 8-bit parallel SRAM compatibility, deterministic 25 ns timing, and capacitor-based AutoStore - making it uniquely suitable for legacy industrial systems where bus architecture and power-loss response predictability are fixed constraints.

Availability

STK22C48-SF25ITR is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostic instruments, and avionics subsystems requiring stable component supply and long-term obsolescence support.

Supply support for STK22C48-SF25ITR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Cypress Semiconductor (now part of Infineon Technologies) is a fabless semiconductor company specializing in memory, microcontrollers, and connectivity solutions for industrial, automotive, and consumer markets.

The STK22C48 belongs to Cypress's nvSRAM product line, engineered specifically for systems needing SRAM-speed access with nonvolatile persistence - targeting applications where power interruption cannot compromise data integrity or system restart reliability.

FAQ

What is the minimum VCAP capacitance required for reliable AutoStore operation?

The STK22C48-SF25ITR requires a minimum 68 µF tantalum or low-ESR electrolytic capacitor on the VCAP pin, rated ≥6 V, to ensure sufficient energy for the full 10 ms STORE cycle when VCC drops below VSWITCH. Capacitance below this value risks incomplete STORE and data loss; values up to 220 µF are supported for extended hold time margin.

Can STK22C48-SF25ITR be used without the VCAP capacitor?

Yes - in AutoStore Inhibit mode, VCC is tied to ground and +5 V is applied directly to VCAP, disabling automatic power-down STORE. In this configuration, STORE is triggered only via HSB pin or software command, eliminating capacitor dependency but requiring explicit firmware control and removing hands-off power-loss protection.

How does the STK22C48-SF25ITR handle simultaneous read and write requests during STORE initiation?

When HSB is asserted or VCC drops, ongoing SRAM reads and writes are allowed to complete within tDELAY (typ. 200 ns), after which all SRAM access is inhibited until STORE finishes. No data corruption occurs: writes in progress finish before STORE begins, and reads return valid data until the STORE lock activates.

Is STK22C48-SF25ITR still recommended for new designs?

No - Cypress explicitly states "Not Recommended for New Designs" in the datasheet. It remains in production solely to support existing industrial and medical programs with long lifecycles. For new designs, Infineon recommends evaluating CY14B101PA-SXIT or FRAM alternatives, though STK22C48-SF25ITR retains full technical support and supply continuity through Aetrix Electronics.