Infineon Technologies STK14C88-NF25TR

Overview

STK14C88-NF25TR from Cypress Semiconductor is a 256 Kb (32K × 8) nonvolatile static RAM with integrated Quantum Trap storage, delivering 25 ns read access time, single 5V ±10% supply operation, and automatic STORE/RECALL on power loss or reset. It functions as a drop-in SRAM replacement in systems requiring persistent data retention without external backup circuitry-used in industrial PLCs, telecom line cards, and medical device configuration memory.

For engineers reviewing the STK14C88-NF25TR datasheet, STK14C88-NF25TR pinout, STK14C88-NF25TR application, or STK14C88-NF25TR equivalent, key selection criteria include AutoStore timing (10 ms), VCAP capacitor interface, HSB hardware store busy signaling, and compatibility with standard parallel SRAM bus protocols at 5V logic levels.

Technical Context

The STK14C88-NF25TR integrates SRAM and nonvolatile Quantum Trap cells monolithically, enabling atomic STORE (SRAM → NV) and RECALL (NV → SRAM) operations. Its control logic supports both hardware-triggered STORE via HSB pin assertion and software-controlled STORE/RECALL through E/W/G sequencing.

It operates in three functional modes: standard SRAM read/write (E/L, W/H or L, G/L), hardware STORE (HSB/L), and AutoStore on VCC dropout detected by internal power monitor. The VCAP pin requires an external 4.7 µF tantalum capacitor to sustain STORE during brownout.

Key Specifications

Pinout & Package

STK14C88-NF25TR uses a 32-pin 300-mil SOIC package (RoHS-compliant), pin-compatible with industry-standard 32K×8 SRAMs. Pin assignments follow JEDEC MS-012AC, with dedicated VCAP and HSB pins enabling autonomous nonvolatile operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK14C88-NF25TR, STK14CA8-NF25TR offers identical functionality with enhanced environmental robustness, while FM24CL64-G trades parallel speed and 5V compatibility for near-infinite endurance and lower voltage operation-requiring board-level redesign.

Availability

STK14C88-NF25TR is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, and medical electronics requiring stable component supply and long-term obsolescence management.

Supply support for STK14C88-NF25TR 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 STK14C88 belongs to Cypress's nvSRAM product line, engineered specifically to eliminate battery-backed SRAM limitations in mission-critical systems requiring guaranteed data persistence without maintenance.

FAQ

What is the required VCAP capacitor value and type for STK14C88-NF25TR?

The STK14C88-NF25TR requires a 4.7 µF tantalum capacitor rated for ≥6.3 V between VCAP and VSS. Ceramic capacitors are not recommended due to insufficient energy storage and ESR characteristics that compromise STORE reliability during fast VCC collapse. Mounting must be within 5 mm of the VCAP pin with low-inductance traces.

Does STK14C88-NF25TR support true hardware STORE without firmware intervention?

Yes-asserting HSB low initiates STORE independently of CPU activity. The device monitors internal power and automatically completes STORE if VCC drops below threshold before HSB is released. No clock, address, or data lines need to be active during this mode, making it suitable for uncontrolled power-fail scenarios.

Can STK14C88-NF25TR be used as a direct replacement for standard 32K×8 SRAMs?

Yes-pinout, timing, and DC specifications match JEDEC-standard 32K×8 SRAMs. However, VCAP must be populated and HSB tied high (via 10 kΩ pull-up) for transparent operation. Unused NC pins must remain unconnected; A13 is not used in 32K addressing but must be driven to valid logic level per datasheet.

What happens if STORE is interrupted by complete power loss before completion?

If VCC collapses before tSTORE (10 ms) elapses, the Quantum Trap cell retains partial charge, resulting in undefined data state upon RECALL. To prevent this, system designers must ensure VCAP holds sufficient energy-verified by measuring VCAP discharge time under worst-case load-and avoid rapid power ramp-down without hold-up circuitry.