Infineon Technologies STK11C88-NF25ITR

Overview

STK11C88-NF25ITR from Cypress Semiconductor is a 256 Kbit (32K × 8) nonvolatile static RAM with QuantumTrap™ nvSRAM technology, delivering 25 ns access time, single 5V ±10% supply operation, and automatic hardware RECALL on power-up. It functions as a drop-in replacement for standard SRAMs in systems requiring persistent data retention without backup batteries or external EEPROM. Used in industrial controllers, metering firmware storage, and POS terminal configuration memory.

For engineers reviewing the STK11C88-NF25ITR datasheet, STK11C88-NF25ITR pinout, STK11C88-NF25ITR application, or STK11C88-NF25ITR equivalent, key selection criteria include software-initiated STORE/RECALL sequence compatibility, 1,000,000 STORE endurance, 100-year data retention, and 28-pin SOIC package footprint alignment with legacy SRAM designs.

Technical Context

The STK11C88-NF25ITR integrates volatile SRAM and nonvolatile QuantumTrap cells in a unified 32K × 8 array, enabling atomic data persistence via software-controlled STORE (six-address CE-read sequence to 0x0E38–0x0FC0) and RECALL (same sequence ending at 0x0C63). Its dual-mode operation supports standard SRAM read/write cycles while isolating nv operations through dedicated control timing.

Hardware RECALL triggers automatically when VCC exceeds VSWITCH after brownout or power-up, completing in tHRECALL ≤ 20 ms. The device enforces hardware protection below VSWITCH, disabling STORE and WRITE to prevent corruption - no external circuitry required beyond a 10 kΩ pull-up on WE or CE for robustness.

Key Specifications

Pinout & Package

28-pin Small Outline Integrated Circuit (SOIC), 300 mil body width, gull-wing leads, RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK11C68-NF25ITR, the STK11C88-NF25ITR provides double memory capacity in identical packaging and timing, while FM24CL64-G trades parallel bus compatibility and hardware RECALL for serial simplicity and infinite write endurance - making it unsuitable as a drop-in replacement but viable for new designs prioritizing write endurance over boot-time determinism.

Availability

STK11C88-NF25ITR is available at Aetrix Electronics and suitable for industrial programmable logic controllers, smart electricity meters, and point-of-sale terminal configuration requiring stable component supply and long-term obsolescence support.

Supply support for STK11C88-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) designs high-reliability memory and programmable solutions for industrial, automotive, and IoT applications, with global manufacturing and quality certification.

The STK11C88 belongs to Cypress's SoftStore® nvSRAM product line, engineered specifically to replace battery-backed SRAM and discrete SRAM+EEPROM combinations in mission-critical embedded systems demanding guaranteed data persistence.

FAQ

What triggers automatic RECALL on power-up?

Automatic RECALL initiates when VCC rises above the internal VSWITCH threshold (~3.0V) after power-up or brownout. The device latches the condition and executes a full RECALL cycle in ≤20 ms (tHRECALL), restoring all 32K bytes from QuantumTrap cells to SRAM without firmware intervention. No external reset signal is required.

Can STK11C88-NF25ITR be used as a direct replacement for standard 28-pin SOIC SRAMs?

Yes - it is pin-compatible with industry-standard 32K × 8 SRAMs (e.g., IS61LV256AL, CY62256) using identical A0–A14, DQ0–DQ7, CE, WE, OE, VCC, and VSS connections. Standard SRAM read/write operations function identically; STORE/RECALL require only firmware integration of the six-address sequence and do not affect existing memory access logic.

What happens if a STORE sequence is interrupted mid-execution?

If any address in the six-cycle CE-read sequence (0x0E38 → 0x0C63) is skipped, misordered, or accompanied by a WE LOW pulse, the sequence aborts immediately. No STORE occurs, SRAM remains fully operational, and no data is written to nonvolatile cells. The device returns to normal SRAM mode with no side effects or state corruption.

Is the 100-year data retention specification tested or extrapolated?

The 100-year retention is an extrapolated specification based on accelerated life testing at elevated temperature (+85°C) and voltage, validated per JESD22-A108 methodology. Cypress documents this value in the official datasheet (001-50591 Rev. *A, Section "Data Retention and Endurance") with statistical confidence bounds and applies conservative derating for industrial temperature operation.