Infineon Technologies STK11C88-NF45

Overview

STK11C88-NF45 from Cypress Semiconductor is a 256 Kbit (32K × 8) nonvolatile static RAM with integrated QuantumTrap nvSRAM technology, operating at 45 ns access time on a single 5V ±10% supply. It performs automatic hardware RECALL on power-up and supports software-initiated STORE/RECALL cycles, delivering 100-year data retention and 1,000,000 STORE endurance for mission-critical data logging in industrial controllers.

For engineers reviewing the STK11C88-NF45 datasheet, STK11C88-NF45 pinout, STK11C88-NF45 application, or STK11C88-NF45 equivalent, key selection criteria include its 28-pin SOIC package compatibility with standard SRAM footprints, deterministic 45 ns tAA timing, and dual-mode recall (power-up and software-triggered) - all critical for fail-safe memory backup in embedded systems with brownout resilience requirements.

Technical Context

The STK11C88-NF45 integrates volatile SRAM and nonvolatile QuantumTrap cells in a unified 32K × 8 array, enabling byte-level read/write without wear-out while preserving data across power loss. Its operation relies on CE-controlled address-sequence protocols: six precise READs to 0x0E38–0x0FC0 initiate STORE; identical sequence ending at 0x0C63 triggers RECALL.

Hardware RECALL activates automatically when VCC exceeds VSWITCH after undervoltage (VCC < VRESET), completing in tHRECALL (max 20 ms). During STORE/RECALL, all I/O is tri-stated and external accesses are blocked - requiring strict sequencing discipline and no intervening writes to avoid abort.

Key Specifications

Pinout & Package

STK11C88-NF45 uses a 28-pin Small Outline Integrated Circuit (SOIC) package with 300 mil body width and standard JEDEC MS-012AC footprint. Pin assignments are validated per Cypress Document 001-50591 Rev. *A, Page 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK11C88-NF25 and FM1808-40-SG, the STK11C88-NF45 offers optimal balance of industrial temperature support, proven QuantumTrap reliability, and 45 ns timing margin for legacy 5V systems - making it the preferred choice for sustaining production of field-deployed equipment where timing slack and supply voltage stability are constrained.

Availability

STK11C88-NF45 is available at Aetrix Electronics and suitable for industrial PLC data logging, smart energy meter firmware backup, and medical infusion pump configuration requiring stable component supply and long-term lifecycle continuity.

Supply support for STK11C88-NF45 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 STK11C88 belongs to Cypress's SoftStore nvSRAM product line, engineered specifically to replace battery-backed SRAM and EEPROM in applications demanding instant nonvolatility, unlimited write endurance, and deterministic power-loss recovery.

FAQ

What is the exact STORE sequence for STK11C88-NF45?

The STORE sequence requires six consecutive CE-controlled READ operations to specific addresses: 0x0E38, 0x31C7, 0x03E0, 0x3C1F, 0x303F, and finally 0x0FC0. All six reads must occur with WE held HIGH and no intervening writes; failure to follow this exact order aborts the operation. The device enters disabled state until tSTORE completes (~15 ms).

Does STK11C88-NF45 require external capacitors?

Yes - a 0.1 µF ceramic bypass capacitor must be placed between VCC and VSS with minimal trace length, as specified in Cypress Document 001-50591 Section 5. This is mandatory to suppress high-frequency noise that could corrupt STORE/RECALL sequences or cause spurious writes in the SRAM array.

Can STK11C88-NF45 operate at 3.3V?

No - STK11C88-NF45 is strictly a 5V-only device with VCC specification of 4.5V to 5.5V. Attempting operation below 4.5V violates Absolute Maximum Ratings and disables hardware RECALL protection, risking data corruption during brownout. For 3.3V systems, consider Infineon's newer nvSRAM families like the CY14B108.

Is STK11C88-NF45 still recommended for new designs?

No - Cypress explicitly states "Not recommended for new designs. In production to support ongoing production programs only." It remains available for legacy program continuity, but new designs should evaluate Infineon's CY14B series or competing F-RAM/nonvolatile FRAM alternatives offering enhanced density, lower voltage, and extended support.