Infineon Technologies STK16C88-3WF35I

Overview

STK16C88-3WF35I from Cypress Semiconductor is a 256 Kbit (32K × 8) AutoStore+ nvSRAM with integrated QuantumTrap nonvolatile storage, delivering 35 ns read access, automatic power-loss STORE and power-up RECALL, and 100-year data retention. It operates from a single 3.3 V ±0.3 V supply, supports industrial temperature range (–40°C to +85°C), and replaces battery-backed SRAMs in mission-critical data logging and configuration storage applications.

For engineers reviewing the STK16C88-3WF35I datasheet, STK16C88-3WF35I pinout, STK16C88-3WF35I application, or STK16C88-3WF35I equivalent, this device offers deterministic nonvolatile write-back without external capacitors or batteries, software-controlled STORE/RECALL sequences, and hardware protection against low-voltage corruption - critical for industrial control, medical instrumentation, and telecom infrastructure where data integrity must survive uncontrolled power cycles.

Technical Context

The STK16C88-3WF35I implements a dual-mode nonvolatile memory architecture: volatile SRAM cells paired with per-cell QuantumTrap nonvolatile elements. STORE occurs automatically when VCC drops below VSWITCH (<500 ns latency), and RECALL initiates on power-up once VCC exceeds VSWITCH, completing in tHRECALL (typ. 10 ms). Both operations are also available via six-address CE-controlled READ sequences.

Hardware protection disables STORE and WRITE when VCAP < VSWITCH, preventing corruption during brownout. The device uses standard parallel SRAM timing (WE, CE, OE active-low controls) and requires no external components beyond a 0.1 µF VCC–VSS bypass capacitor. It is not recommended for new designs but remains in production to support legacy industrial programs.

Key Specifications

Pinout & Package

28-pin Plastic Dual In-line Package (PDIP), 600 mil width, RoHS-compliant. Pin 1 marked by notch or dot; pin numbering follows standard counter-clockwise layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY14B108L-ZSP25XI and DS1248W-120+, the STK16C88-3WF35I uniquely combines 35 ns speed, true AutoStore+ autonomy, industrial PDIP packaging, and battery-free operation - making it irreplaceable in existing 8-bit parallel bus designs requiring guaranteed power-loss resilience without redesign.

Availability

STK16C88-3WF35I is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostic instruments, telecom infrastructure, and avionics subsystems requiring stable component supply and long-term lifecycle support.

Supply support for STK16C88-3WF35I 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 STK16C88-3WF35I belongs to Cypress's AutoStore+ nvSRAM product line, designed specifically to eliminate batteries and external capacitors in mission-critical data retention applications while maintaining pin compatibility with standard SRAMs.

FAQ

What triggers automatic STORE on the STK16C88-3WF35I?

Automatic STORE initiates when VCC drops below VSWITCH (typically ~2.7 V), detected by internal circuitry. The operation completes within 500 ns using charge stored in an on-die capacitor - no external components are needed. STORE is suppressed unless at least one WRITE has occurred since the last STORE or RECALL, preventing unnecessary wear on the nonvolatile elements.

Can STK16C88-3WF35I be used in new designs?

No - Cypress explicitly marks the STK16C88-3WF35I as "Not recommended for new designs." It remains in production solely to support ongoing manufacturing programs. New designs should evaluate Infineon's CY14B series or alternative nvSRAMs with extended lifetime and modern packaging.

How does software STORE differ from hardware STORE?

Software STORE is initiated by a precise six-address CE-controlled READ sequence (ending at 0x0FC0), enabling on-demand nonvolatile save regardless of VCC level. Hardware STORE activates only on power loss and is fully transparent. Software STORE disables I/O until completion (tSTORE ≈ 10 ms), while hardware STORE occurs concurrently with power collapse and does not block host access beforehand.

Is the 28-pin PDIP package lead-free and RoHS compliant?

Yes - the STK16C88-3WF35I is RoHS compliant and uses lead-free terminations per JEDEC J-STD-609. The "W" in the part number denotes RoHS-compliant packaging. The PDIP body is molded epoxy with matte tin-plated leads, qualified for wave and hand soldering per IPC-J-STD-020.