Infineon Technologies STK22C48-NF25ITR

Overview

STK22C48-NF25ITR 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. Used in industrial control systems for real-time parameter backup during unexpected power loss.

For engineers reviewing the STK22C48-NF25ITR datasheet, STK22C48-NF25ITR pinout, STK22C48-NF25ITR application, or STK22C48-NF25ITR equivalent, key selection criteria include AutoStore timing behavior, VCAP capacitor sizing (68 µF), HSB-driven hardware STORE control, and compatibility with 28-pin SOIC-300 mil layouts in legacy 5 V systems.

Technical Context

The STK22C48-NF25ITR combines a standard fast SRAM array (32 × 512) with parallel QuantumTrap nonvolatile storage cells. STORE transfers data from SRAM to nonvolatile elements on power-down (AutoStore), via HSB assertion, or through software command; RECALL restores data on power-up or via software.

It uses a dual-power architecture: VCC supplies active operation while VCAP (charged via internal circuitry) powers the STORE cycle when VCC drops below VSWITCH (~3.6 V). The HSB pin serves both as STORE request input and open-drain busy indicator, requiring external 10 kΩ pull-up to VCAP when used as output.

Key Specifications

Pinout & Package

STK22C48-NF25ITR is housed in a 28-pin Small Outline Integrated Circuit (SOIC) package, 300 mil body width, RoHS-compliant, with standard JEDEC MO-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY14B101PA-SP25XI and FM24CL16B-G, STK22C48-NF25ITR uniquely delivers parallel 5 V interface, deterministic 25 ns timing, and true hands-off AutoStore-making it optimal for drop-in replacement in legacy industrial controllers where bus architecture and power-loss response are fixed.

Availability

STK22C48-NF25ITR is available at Aetrix Electronics and suitable for PLC parameter backup, motor drive fault logging, and medical infusion pump calibration requiring stable component supply and long-lifecycle support.

Supply support for STK22C48-NF25ITR 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 applications.

The STK22C48 belongs to Cypress's AutoStore nvSRAM product line, engineered specifically for mission-critical systems requiring instantaneous, reliable, and maintenance-free nonvolatile data capture during power failure.

FAQ

What is the minimum VCAP capacitor value required for reliable AutoStore operation?

The STK22C48-NF25ITR requires a minimum 68 µF tantalum or low-ESR electrolytic capacitor on the VCAP pin, rated for ≥6 V. This value ensures sufficient stored energy to complete the 10 ms STORE cycle when VCC collapses from 5 V to below VSWITCH (~3.6 V). Capacitor tolerance must be within ±20%, and ESR should be ≤1 Ω to avoid voltage droop during discharge.

Can STK22C48-NF25ITR operate without the VCAP capacitor?

No-VCAP is mandatory for AutoStore functionality. In AutoStore Inhibit mode (VCC grounded, +5 V applied to VCAP), the capacitor is still required to power STORE operations initiated via HSB. Omitting VCAP disables all nonvolatile STORE capability, reducing the device to a standard volatile SRAM with no data retention on power loss.

How does the STK22C48-NF25ITR prevent unintended STORE during brown-out conditions?

The device monitors VCC and inhibits all STORE operations-including AutoStore and HSB-triggered STORE-when VCC falls below VSWITCH (~3.6 V). Additionally, SRAM writes are blocked under the same condition. This dual-lock mechanism prevents partial or corrupted STOREs and ensures only full-voltage, valid STORE cycles execute, preserving data integrity across unstable power events.

Is STK22C48-NF25ITR pin-compatible with standard 28-pin SOIC SRAMs like the IS61LV256AL?

Yes-STK22C48-NF25ITR uses the same 28-pin SOIC-300 mil footprint and pinout as industry-standard 2 K × 8 SRAMs, including address (A0–A10), data (DQ0–DQ7), and control (CE, OE, WE) signals. However, VCAP and HSB pins replace two NC pins found on conventional SRAMs, requiring minor PCB layout adaptation to accommodate those functions.