Infineon Technologies STK11C88-NF25

Overview

STK11C88-NF25 from Cypress Semiconductor is a 256 Kbit (32K × 8) nonvolatile static RAM with integrated QuantumTrap™ nvSRAM technology, operating at 5 V ±10%, delivering 25 ns access time and supporting software-initiated STORE/RECALL as well as automatic hardware RECALL on power-up. It functions as a drop-in replacement for standard SRAM in systems requiring persistent data retention without backup batteries or external EEPROM.

For engineers reviewing the STK11C88-NF25 datasheet, STK11C88-NF25 pinout, STK11C88-NF25 application, or STK11C88-NF25 equivalent, key selection considerations include its 28-pin SOIC package, unlimited SRAM read/write endurance, 1,000,000 STORE cycles, 100-year data retention, and deterministic software-controlled nonvolatile transfer sequences.

Technical Context

The STK11C88-NF25 integrates volatile SRAM and nonvolatile QuantumTrap cells in a single monolithic die, enabling atomic STORE (SRAM → nv) and RECALL (nv → SRAM) operations. Its dual-mode operation-standard SRAM read/write plus nonvolatile control via six-address CE-controlled READ sequences-eliminates need for external controllers or firmware overhead beyond sequence execution.

Hardware RECALL triggers automatically when VCC exceeds VSWITCH after brownout or power-up, completing in tHRECALL (max 20 ms). The device enforces hardware protection below VSWITCH, disabling STORE and WRITE to prevent corruption during low-voltage transients.

Key Specifications

Pinout & Package

STK11C88-NF25 uses a 28-pin Small Outline Integrated Circuit (SOIC) package with 300-mil body width, JEDEC MS-012AC compliant, suitable for automated placement and thermal management in dense layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK11C68-NF25, the STK11C88-NF25 offers double memory capacity with identical timing and control logic; versus FM1808-250, it provides guaranteed 5 V compatibility and deterministic hardware RECALL-critical for retrofitting legacy industrial hardware.

Availability

STK11C88-NF25 is available at Aetrix Electronics and suitable for industrial PLC data logging, point-of-sale transaction buffering, and metering calibration storage requiring stable component supply and long-term obsolescence support.

Supply support for STK11C88-NF25 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 U.S.-based semiconductor company specializing in memory, microcontrollers, and programmable solutions for industrial, automotive, and consumer applications.

The STK11C88 belongs to Cypress's SoftStore® nvSRAM product line, engineered to replace battery-backed SRAM in mission-critical systems where maintenance-free, long-life nonvolatility is mandatory.

FAQ

What triggers automatic RECALL on power-up?

Automatic RECALL initiates when VCC rises above the internal VSWITCH threshold (~3.0 V) after power-up or brownout recovery. The device latches the request internally and executes RECALL within tHRECALL (max 20 ms), restoring the last stored data to SRAM without firmware intervention.

Can STORE and RECALL be performed while the system is running?

Yes-both operations are software-initiated via six consecutive CE-controlled READs to specific addresses (0x0E38 through 0x0FC0 for STORE; 0x0C63 for RECALL). During execution, the device disables I/O and halts SRAM access until completion (tSTORE ≈ 15 ms, tRECALL ≈ 10 ms).

Is the STK11C88-NF25 pin-compatible with standard 28-pin SRAMs?

Yes-it matches industry-standard 32K × 8 SRAM pinouts (e.g., IS61LV256AL), including identical A0–A14, DQ0–DQ7, CE, OE, WE, VCC, and VSS assignments. No PCB redesign is needed for drop-in replacement in existing 5 V systems.

Why does the datasheet state "Not recommended for new designs"?

This reflects Cypress's product lifecycle status: STK11C88-NF25 remains in active production solely to support ongoing manufacturing programs, not for new design starts. Aetrix guarantees continued supply and long-term availability for legacy system maintenance and repair.