Infineon Technologies STK14CA8-NF45I

Overview

STK14CA8-NF45I from Cypress Semiconductor is a 128K × 8 (1 Mb) nonvolatile static RAM with integrated QuantumTrap storage, delivering 45 ns read/write cycle time, automatic STORE on power loss and RECALL on power-up, and single 3.0V ±10% operation. It provides unlimited SRAM read/write endurance, 200K nonvolatile STORE cycles, and 20-year data retention at 55°C - deployed in industrial control logging, metering backup memory, and real-time event capture systems.

For engineers reviewing the STK14CA8-NF45I datasheet, STK14CA8-NF45I pinout, STK14CA8-NF45I application, or STK14CA8-NF45I equivalent, key selection criteria include AutoStore timing (12.5 ms), VCAP capacitor requirement (17–120 µF), HSB hardware store busy signaling, and compatibility with 32-pin SOIC footprint for legacy board replacement.

Technical Context

The STK14CA8-NF45I integrates a 1024 × 1024 SRAM array with per-cell QuantumTrap nonvolatile storage, enabling monolithic, byte-level nonvolatility without external EEPROM or battery. Its dual-mode STORE operation supports both automatic detection of VCC drop below 2.65 V and software- or hardware-initiated (via HSB pin) nonvolatile save.

It operates exclusively in asynchronous parallel interface mode with standard SRAM timing controls (E, G, W), full address/data bus (A0–A16, DQ0–DQ7), and dedicated VCAP pin for energy storage during power failure. The device requires no external clock or configuration registers - all nonvolatile functions are managed internally via power monitoring and state machine logic.

Key Specifications

Pinout & Package

STK14CA8-NF45I is packaged in a 32-pin Small Outline Integrated Circuit (SOIC) with 0.3-inch body width and RoHS-compliant finish. Pin layout matches JEDEC MS-012AC standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY14B101PA-SP25XI and FM1808-40-TG, STK14CA8-NF45I uniquely delivers parallel SRAM compatibility, 200K STORE cycles, and 20-year retention - making it optimal for industrial retrofits and safety-critical data preservation where bus architecture and lifecycle assurance are mandatory.

Availability

STK14CA8-NF45I is available at Aetrix Electronics and suitable for industrial data loggers, smart metering systems, and railway signaling controllers requiring stable component supply and long-term obsolescence management.

Supply support for STK14CA8-NF45I 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 programmable solutions for industrial, automotive, and communications markets.

The STK14CA8 belongs to Cypress's nvSRAM product line, engineered to replace battery-backed SRAM and serial EEPROM in mission-critical applications demanding zero-data-loss power fail recovery and field-upgradeable nonvolatility.

FAQ

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

The VCAP pin connects to an external electrolytic or tantalum capacitor (17–120 µF, 5 V rated) that supplies energy to complete the nonvolatile STORE operation when VCC drops below 2.65 V. A 47 µF capacitor is commonly used to ensure ≥10 ms hold-up time under worst-case load and temperature conditions, satisfying the 12.5 ms STORE duration spec.

Can STK14CA8-NF45I be used as a drop-in replacement for standard SRAM?

Yes - it is pin- and timing-compatible with industry-standard 128K × 8 parallel SRAMs (e.g., IS61LV1024) when operating in SRAM mode. However, VCAP must be populated, HSB should be monitored if STORE status is needed, and software must avoid issuing commands during STORE/RECALL (indicated by HSB low).

How does AutoStore differ from software-controlled STORE?

AutoStore triggers autonomously when VCC falls below 2.65 V, requiring no host intervention. Software STORE uses a defined 8-byte command sequence written to DQ0–DQ7 while E and W are asserted - enabling precise save points (e.g., after critical calculation) independent of power conditions.

Is STK14CA8-NF45I suitable for new designs despite "Not Recommended for New Designs" in the datasheet?

While Cypress marked STK14CA8 as "Not Recommended for New Designs" in 2009 due to newer nvSRAM families (e.g., CY14B1xx), it remains actively stocked and supported by multiple authorized distributors. Its proven reliability, full documentation, and mature qualification make it viable for maintenance, replacement, and cost-sensitive industrial designs where migration effort is unjustified.