Infineon Technologies STK14C88-3NF45I

Overview

STK14C88-3NF45I from Cypress Semiconductor is a 256 Kbit (32K × 8) nonvolatile static RAM with automatic STORE on power loss, 45 ns access time, single 3.3V supply, and QuantumTrap nonvolatile cell technology. It functions as a drop-in SRAM replacement in systems requiring persistent data retention without external backup power or battery, such as industrial controllers and metering hardware.

For engineers reviewing the STK14C88-3NF45I datasheet, STK14C88-3NF45I pinout, STK14C88-3NF45I application, or STK14C88-3NF45I equivalent, key selection criteria include AutoStore timing behavior, VCAP capacitor sizing (68–220 µF), HSB-controlled STORE synchronization, and software STORE/RECALL address sequence validation.

Technical Context

The STK14C88-3NF45I integrates a standard fast SRAM array (512 × 512) with parallel-connected QuantumTrap nonvolatile cells per bit. STORE and RECALL operate atomically across all 32,768 bytes, with SRAM access inhibited during both operations.

It supports three STORE initiation modes: automatic (on VCC drop below VSWITCH), hardware (via HSB pin assertion), and software (six-address CE-controlled READ sequence). RECALL occurs automatically at power-up or via identical six-address software sequence, with tHRECALL = 15 ms (max) and tRECALL = 12 ms (max).

Key Specifications

Pinout & Package

32-pin SOIC (300-mil width), RoHS-compliant, surface-mount package with standard JEDEC footprint. Pin pitch: 1.27 mm; body width: 7.5 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK14C88-3NF45I, STK14CA8-3AF45I offers lower power with identical functionality, while FM24V01A-G trades AutoStore autonomy for zero-write-latency F-RAM-but lacks integrated power-loss sensing and requires external circuitry for persistence.

Availability

STK14C88-3NF45I is available at Aetrix Electronics and suitable for industrial PLC data logging, energy metering, medical device event history, and telecom base station configuration requiring stable component supply and long-lifecycle support.

Supply support for STK14C88-3NF45I 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 IoT applications.

The STK14C88 product line delivers nonvolatile SRAMs optimized for deterministic data persistence in power-unstable environments-targeting metering, control, and safety-critical logging where battery backup is impractical.

FAQ

What is the minimum VCAP capacitance required for guaranteed STORE operation?

The STK14C88-3NF45I requires a minimum 68 µF tantalum or polymer capacitor rated at 4.7V on the VCAP pin. Capacitance below this value risks incomplete STORE under worst-case VCC droop rates (>20 µs/V), especially at high temperature or with large PCB trace inductance. Derating to 100 µF is recommended for production robustness.

Can the HSB pin be left unconnected in AutoStore-only applications?

Yes-HSB has an internal weak pull-up and is optional for AutoStore-only use. Leaving it unconnected disables hardware STORE initiation and removes the need for external pull-up resistors. However, monitoring HSB is strongly advised to detect STORE progress and prevent host access during the operation, which lasts up to 12 ms.

Does the software STORE sequence require OE to be asserted?

No-OE may be HIGH or LOW during the six-address software STORE sequence. Only CE-controlled READ cycles matter; DQ lines are not driven during the sequence, and OE state does not affect validity. However, OE must remain HIGH during subsequent SRAM writes to avoid bus contention after STORE completion.

Is the STK14C88-3NF45I suitable for new designs given its "Not Recommended for New Designs" status?

While marked "Not Recommended for New Designs" in Cypress documentation, the STK14C88-3NF45I remains actively manufactured and supported by Infineon with confirmed 2027+ availability. It is appropriate for cost-sensitive, long-lifecycle industrial designs where qualification effort outweighs migration to newer alternatives like STK14CA8, especially when existing firmware and layout are validated.