Infineon Technologies STK14C88-L45I

Overview

STK14C88-L45I from Cypress Semiconductor is a 32K × 8 (256 Kb) nonvolatile static RAM with AutoStore functionality, operating at 45 ns read/write cycle time on a single 5V ±10% supply. It integrates Quantum Trap nonvolatile storage per cell, enabling automatic STORE on power loss and RECALL on power-up. Used in industrial control data logging where power interruption resilience is critical.

For engineers reviewing the STK14C88-L45I datasheet, STK14C88-L45I pinout, STK14C88-L45I application, or STK14C88-L45I equivalent, key selection criteria include guaranteed 45 ns access timing, hardware/software-controlled STORE/RECALL, 100-year data retention, unlimited SRAM endurance, and VCAP-backed power-loss protection.

Technical Context

The STK14C88-L45I implements monolithic nvSRAM architecture with dual-mode operation: standard SRAM interface (E/W/G control) and nonvolatile management via HSB-triggered or software-initiated STORE/RECALL. Its Quantum Trap cells eliminate external EEPROM or battery backup.

STORE is initiated either by voltage drop detection (AutoStore), external HSB pull-down, or software command; RECALL occurs automatically at power-up or on demand. The device supports both TTL- and CMOS-compatible input levels and maintains tristate outputs during standby or STORE execution.

Key Specifications

Pinout & Package

32-pin 300-mil SOIC (RoHS-compliant) package with standard parallel memory footprint compatible with industry-standard socket layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK14C88-L45I, STK14CA8-45I offers identical functionality with lower power and longer lifecycle, while FM24CL64-G trades AutoStore autonomy for serial interface simplicity and FRAM endurance - choice depends on whether deterministic power-loss response or interface consolidation is prioritized.

Availability

STK14C88-L45I is available at Aetrix Electronics and suitable for industrial PLC data logging, medical device parameter storage, and avionics black box buffer applications requiring stable component supply and long-term obsolescence support.

Supply support for STK14C88-L45I 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 connectivity solutions for industrial, automotive, and consumer markets.

The STK14C88 belongs to Cypress's nvSRAM product line, designed specifically to replace battery-backed SRAM and discrete EEPROM+SRAM combinations in mission-critical systems demanding zero-data-loss reliability.

FAQ

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

The STK14C88-L45I requires a minimum 4.7 µF tantalum capacitor on the VCAP pin to guarantee successful STORE completion during a 10 ms power interruption. Lower values risk incomplete transfer to Quantum Trap cells, resulting in data corruption. Ceramic capacitors are not recommended due to insufficient charge hold-up time and DC bias derating effects.

Can STK14C88-L45I operate in software-only STORE/RECALL mode without connecting VCAP?

No. VCAP is mandatory for all STORE operations - including software-initiated ones - because it supplies the charge pump that powers the nonvolatile storage circuitry. Without VCAP, STORE commands will stall indefinitely and HSB will remain high; the device functions only as volatile SRAM until VCAP is properly installed.

Is the STK14C88-L45I pin-compatible with standard 32-pin SOIC SRAMs like the AS6C4008?

Yes, it shares the same 32-pin SOIC footprint and signal mapping (A0–A14, DQ0–DQ7, E, W, G, VCC, VSS), but differs in HSB and VCAP pin assignments. HSB replaces NC on many SRAMs, and VCAP occupies a dedicated pin not used in volatile SRAMs - PCB layout must allocate space and routing for both.

Does the "L45I" suffix indicate lead-free and industrial temperature range?

Yes. The "L" denotes lead-free (RoHS-compliant) packaging, "45" specifies 45 ns access time, and "I" designates industrial temperature range (–40°C to +85°C). This suffix aligns with Cypress's standard ordering nomenclature and is verified in the official datasheet revision *B.