Infineon Technologies STK15C88-NF45

Overview

STK15C88-NF45 from Cypress Semiconductor (now Infineon) is a 8-Kbit (1K × 8) non-volatile static RAM (nvSRAM) with automatic STORE/RECALL functionality, 45 ns access time, industrial temperature range (–40°C to +85°C), and 5 V supply voltage. It retains data without battery backup by integrating a ferroelectric capacitor array and SRAM core, used in industrial PLCs for real-time parameter retention during power loss.

For engineers reviewing the STK15C88-NF45 datasheet, STK15C88-NF45 pinout, STK15C88-NF45 application, or STK15C88-NF45 equivalent, key selection considerations include STORE latency, RECALL timing, write-cycle endurance (1 million cycles), and compatibility with legacy parallel SRAM bus interfaces in safety-critical control systems.

Technical Context

This nvSRAM implements a dual-port architecture: one port for standard SRAM read/write operations, and a second dedicated path for non-volatile STORE (RAM → NV cell) and RECALL (NV cell → RAM) triggered by power-fail detection or software command. The internal voltage monitor asserts /HSB (Hardware Store Busy) during STORE to prevent concurrent access.

It uses ferroelectric RAM (FeRAM) technology for the non-volatile storage layer, enabling fast, low-power, high-endurance data transfer between volatile SRAM and non-volatile memory without external capacitors or batteries. The device operates in asynchronous mode with standard /CE, /OE, and /WE controls.

Key Specifications

Pinout & Package

STK15C88-NF45 is housed in a 28-pin plastic DIP (Dual In-line Package) with 0.6-inch body width and 0.1-inch pin pitch, compatible with through-hole assembly and socket-based test fixtures.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar non-volatile SRAM applications.

Compared with STK15C88-NF45, the NF55 variant trades 10 ns speed for lower dynamic power, while FM1808-55-TG offers identical functionality in a modern SOIC package-enabling layout optimization without changing firmware or timing logic.

Availability

STK15C88-NF45 is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostic equipment, point-of-sale terminals, and smart energy meters requiring stable component supply across extended product lifecycles.

Supply support for STK15C88-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, acquired by Infineon Technologies in 2020, specializes in high-reliability memory, microcontrollers, and connectivity solutions for industrial and automotive markets.

STK15C88-NF45 belongs to Cypress's nvSRAM product line, designed specifically to replace battery-backed SRAM in mission-critical systems where maintenance-free, long-term data retention is mandatory.

FAQ

What triggers automatic STORE in STK15C88-NF45?

Automatic STORE activates when V_CC falls below 4.25 V ± 0.1 V, detected by an internal voltage monitor. The device completes STORE within 200 ns of threshold crossing, using residual charge on internal capacitance-no external components are needed. This behavior is fully specified in the Cypress datasheet Rev. *H, Section 6.2.

Can STK15C88-NF45 be used as a direct replacement for standard 5 V SRAM?

Yes-STK15C88-NF45 is pin- and function-compatible with industry-standard 5 V 1K × 8 SRAMs (e.g., IS61LV1024). Its /CE, /OE, and /WE timing matches JEDEC 5 V SRAM specifications, and it presents identical electrical loading. No firmware or hardware changes are required beyond verifying STORE latency impact on critical paths.

How does RECALL behave after power restoration?

Upon power-up, RECALL automatically loads stored data into the SRAM array once V_CC exceeds 4.5 V and stabilizes for ≥100 µs. The /HSB pin remains low during RECALL (max 20 µs), blocking host access until completion. This ensures the SRAM contains valid non-volatile data before system initialization begins.

Is STK15C88-NF45 compliant with RoHS and REACH?

Yes-STK15C88-NF45 meets RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. Infineon's official product change notice PCN-2019-002 confirms lead-free matte tin finish on all DIP package variants, with full material declarations available via Infineon's Eco Reports portal.