Infineon Technologies STK14D88-NF45ITR

Overview

STK14D88-NF45ITR from Cypress Semiconductor is a 32K × 8 (256 Kb) nonvolatile static RAM with AutoStore functionality, operating on a single 3.0 V ±10% supply, offering 45 ns read/write cycle time, unlimited SRAM read/write endurance, and 20-year data retention. It performs automatic nonvolatile STORE on power loss and RECALL on power-up, and supports hardware- or software-controlled STORE/RECALL in industrial temperature range (–40°C to +85°C).

For engineers reviewing the STK14D88-NF45ITR datasheet, STK14D88-NF45ITR pinout, STK14D88-NF45ITR application, or STK14D88-NF45ITR equivalent, this nvSRAM delivers deterministic power-loss data preservation without external controllers, eliminates battery backup, and enables robust data logging in mission-critical embedded systems where write-cycle reliability and zero-latency recall are essential.

Technical Context

The STK14D88 integrates a standard fast SRAM array (512 × 512) with Quantum Trap nonvolatile storage cells per bit, enabling monolithic, single-chip nonvolatility. Its STORE operation transfers data from SRAM to nonvolatile elements when VCC drops below 2.65 V or upon HSB assertion; RECALL restores data at power-up after VCC exceeds 2.65 V within 150 μs rise time.

It supports three operational modes: standard SRAM access (E/G/W control), hardware-triggered STORE via HSB pin, and software-controlled STORE/RECALL using command sequences. The device requires an external 17–120 μF tantalum or ceramic capacitor on VCAP to sustain STORE for ≥12.5 ms, and maintains tri-state outputs during STORE/RECALL to prevent bus contention.

Key Specifications

Pinout & Package

STK14D88-NF45ITR is packaged in a 32-pin Small Outline Integrated Circuit (SOIC) with 300 mil body width, RoHS-compliant, surface-mount footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK14C88-NF45I, the STK14D88-NF45ITR adds industrial temperature support and doubles STORE endurance; compared with FM24V01A-G, it embeds autonomous power-loss response but trades off infinite write cycles for fixed 200K STORE limit.

Availability

STK14D88-NF45ITR is available at Aetrix Electronics and suitable for industrial data loggers, programmable logic controllers, medical diagnostic buffers, and smart metering systems requiring stable component supply and long-term lifecycle assurance.

Supply support for STK14D88-NF45ITR 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 communications markets.

The STK14D88 belongs to Cypress's nvSRAM product line, engineered to replace battery-backed SRAM and EEPROM in applications demanding instant nonvolatility, deterministic STORE timing, and zero-maintenance data retention.

FAQ

What is the purpose of the VCAP pin, and what capacitor value is required?

The VCAP pin connects to an external storage capacitor that supplies energy during power loss to complete the nonvolatile STORE operation. Cypress specifies a minimum of 17 μF and maximum of 120 μF, rated for 5 V, with low ESR (e.g., tantalum or multilayer ceramic). Using <17 μF risks incomplete STORE; >120 μF extends recharge time and may delay subsequent operations.

Can STK14D88-NF45ITR be used as a direct replacement for standard SRAM?

Yes - it is pin- and function-compatible with standard 32K × 8 SRAMs (e.g., AS6C4008, IS61LV256AL) in read/write operations. All control signals (E, W, G), address/data buses, and timing match. However, VCAP must be populated, and HSB should be monitored or left floating with its internal weak pull-up; unused pins (e.g., NC) must remain unconnected.

How does AutoStore differ from software-controlled STORE?

AutoStore triggers automatically when VCC drops below 2.65 V, requiring no host intervention. Software STORE uses a specific 8-byte command sequence written to DQ0–DQ7 while E and W are asserted in a precise timing window. AutoStore ensures fail-safe persistence; software STORE enables selective saving of critical subsets or conditional saves based on application state.

Is STK14D88-NF45ITR recommended for new designs?

No - Cypress explicitly marks STK14D88 as "Not Recommended for New Designs" in its datasheet (Rev. *A, Dec 2009). While fully functional and supported for legacy repair and continuity, Infineon recommends newer nvSRAM families (e.g., CY14B108QN) with enhanced density, lower power, and extended lifecycle support for new projects.