Infineon Technologies STK14CA8-NF35TR

Overview

STK14CA8-NF35TR from Cypress Semiconductor is a 128K × 8 (1 Mb) nonvolatile static RAM with integrated QuantumTrap storage, delivering 35 ns read/write cycle time, single 3.0V ±10% operation, and automatic STORE/RECALL on power loss/power-up. It provides unlimited SRAM read/write endurance, 20-year data retention at 55°C, and operates across industrial temperature range (–40°C to +85°C) in 32-pin SOIC package. Used in industrial PLCs for real-time parameter backup without external battery or EEPROM.

For engineers reviewing the STK14CA8-NF35TR datasheet, STK14CA8-NF35TR pinout, STK14CA8-NF35TR application, or STK14CA8-NF35TR equivalent, key selection criteria include AutoStore timing (12.5 ms), VCAP capacitor requirement (17–120 µF), HSB hardware store busy signaling, software-controlled STORE/RECALL command support, and compatibility with standard SRAM bus protocols.

Technical Context

The STK14CA8-NF35TR integrates a 1024 × 1024 SRAM array with per-cell QuantumTrap nonvolatile storage, enabling monolithic, battery-free data persistence. Its dual-mode STORE operation supports both automatic detection of VCC drop below 2.65 V and explicit initiation via HSB pin assertion or software command sequence.

RECALL occurs automatically on power-up when VCC rises above 2.65 V, completing within 20 ms; it also supports software-triggered recall. The device maintains full SRAM timing compliance (tAVAV = 35 ns) during normal operation while isolating nonvolatile cycles - WRITE commands are ignored during STORE/RECALL, and outputs tri-state when VCC is below VSWITCH.

Key Specifications

Pinout & Package

STK14CA8-NF35TR is packaged in a 32-pin Small Outline Integrated Circuit (SOIC) with 0.3-inch body width and RoHS-compliant finish. Pin layout follows JEDEC MS-012AC, with standard address/data/control signal mapping aligned to industry SRAM footprints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK14C88-NF35TR, the STK14CA8-NF35TR offers simpler control with no /HOLD pin dependency but less flexibility in STORE suppression; versus FM1808-35-SG, it provides faster 35 ns timing and hardware-fallback STORE assurance critical for safety-critical brownout response.

Availability

STK14CA8-NF35TR is available at Aetrix Electronics and suitable for industrial automation, smart metering, and railway signaling applications requiring stable component supply, long-term lifecycle support, and guaranteed nonvolatile memory performance under voltage transients.

Supply support for STK14CA8-NF35TR 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 infrastructure markets.

The STK14CA8 product line delivers monolithic nvSRAM for applications demanding battery-free, high-endurance, and deterministic nonvolatile storage - targeting systems where EEPROM latency, FRAM cost, or battery maintenance are unacceptable.

FAQ

What is the minimum VCAP capacitance required for reliable AutoStore operation?

The STK14CA8-NF35TR requires a minimum 17 µF capacitor between VCAP and VSS, rated for ≥5 V, to sustain the 12.5 ms STORE duration during worst-case VCC collapse. Tantalum or low-ESR ceramic capacitors are recommended; insufficient capacitance causes incomplete STORE and data corruption.

Can STK14CA8-NF35TR be used as a direct replacement for standard 32-pin SOIC SRAMs?

Yes - it is pin- and timing-compatible with standard 128K×8 SRAMs (e.g., IS61LV1024) for read/write operations. However, VCAP must be added, HSB should be pulled up via 10 kΩ, and firmware must avoid issuing commands during STORE/RECALL windows to prevent bus contention.

Does the device perform STORE during a controlled software shutdown?

No - AutoStore triggers only on VCC drop below 2.65 V. For controlled shutdown, the host must issue the documented 3-byte software STORE command before power removal. This ensures only selected memory regions are saved, reducing STORE time and extending nonvolatile cycle life.

Is the 20-year data retention specification tested or calculated?

The 20-year retention is an extrapolated specification validated per JESD22-A108 High Temperature Operating Life testing at 125°C and 85°C, with Arrhenius modeling confirming >20 years at 55°C. Cypress provides full qualification reports upon request for medical and rail certification submissions.