Infineon Technologies STK14C88-3NF35ITR

Overview

STK14C88-3NF35ITR from Cypress Semiconductor is a 256 Kbit (32K × 8) nonvolatile SRAM with AutoStore functionality, QuantumTrap nonvolatile cell architecture, 35 ns access time, single 3.3 V supply, and industrial temperature range (–40°C to +85°C). It performs automatic STORE on power loss and RECALL on power-up, used in mission-critical data logging and configuration retention systems where volatile memory persistence is required without external backup circuitry.

For engineers reviewing the STK14C88-3NF35ITR datasheet, STK14C88-3NF35ITR pinout, STK14C88-3NF35ITR application, or STK14C88-3NF35ITR equivalent, key selection criteria include VCAP capacitor sizing (68–220 µF), HSB timing coordination for multi-device STORE synchronization, tSTORE/tRECALL cycle durations, and software address sequence validation for controlled STORE/RECALL initiation.

Technical Context

The STK14C88-3NF35ITR integrates parallel SRAM and QuantumTrap nonvolatile storage per cell, enabling simultaneous STORE/RECALL across all 32,768 bytes. Its dual-mode STORE control supports hardware-triggered (HSB pin) and software-initiated (6-address CE-read sequence) operations, with automatic inhibition unless at least one SRAM write occurs since last nonvolatile cycle.

RECALL is triggered automatically at power-up when VCC exceeds VSWITCH (typ. 2.7 V), completing in tHRECALL ≤ 20 ms. During STORE or RECALL, SRAM read/write is inhibited, and HSB asserts low as open-drain busy signal-requiring external 10 kΩ pull-up to VCAP when used for synchronization.

Key Specifications

Pinout & Package

STK14C88-3NF35ITR uses a 32-pin SOIC package (300-mil width), RoHS-compliant, with standard pin pitch and thermal profile suitable for reflow soldering in industrial PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK14CA8-3AF35I, the STK14C88-3NF35ITR provides broader temperature support and SOIC packaging for automated assembly; versus FM24V01A-G, it delivers true hands-off power-loss protection but trades off unlimited write cycles for 1M STORE limit and capacitor dependency.

Availability

STK14C88-3NF35ITR is available at Aetrix Electronics and suitable for industrial PLC configuration storage, medical device calibration data retention, and telecom base station parameter backup requiring stable component supply and long-term lifecycle assurance.

Supply support for STK14C88-3NF35ITR 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, with emphasis on mixed-signal integration and data integrity.

The STK14C88-3 product line delivers nonvolatile SRAMs optimized for systems needing instant-on data persistence without batteries or external controllers-targeting infrastructure equipment where firmware simplicity and regulatory compliance are critical.

FAQ

What capacitor value and voltage rating are required for VCAP?

A 68 µF to 220 µF tantalum or low-ESR electrolytic capacitor rated at ≥4.7 V must be connected between VCAP and VSS. The capacitor must be placed within 10 mm of the STK14C88-3NF35ITR package to minimize inductance and ensure reliable STORE energy delivery during VCC dropout.

Can STK14C88-3NF35ITR operate without the VCAP capacitor?

No. VCAP is mandatory for AutoStore functionality. Without it, power-loss STORE fails, and the device operates only in software-controlled STORE mode-if VCC is tied to ground and +3.3 V applied to VCAP (AutoStore Inhibit mode), but this requires hardware redesign and forfeits automatic protection.

How does the HSB pin function during multi-device STORE synchronization?

When multiple STK14C88-3NF35ITR devices share a common HSB bus and VCAP capacitor, any device detecting VCC drop pulls HSB LOW, causing all connected devices to initiate STORE simultaneously. Each device only executes STORE if it has undergone at least one SRAM write since its last nonvolatile cycle.

Is the software STORE sequence compatible with standard memory-mapped bus interfaces?

Yes-the six-address CE-controlled READ sequence (0x0E38, 0x31C7, 0x03E0, 0x3C1F, 0x303F, 0x0FC0) uses standard SRAM timing and requires no special bus protocol. However, intervening reads/writes between steps abort the sequence, so bus arbitration must guarantee uninterrupted access during the 6-cycle window.