Infineon Technologies STK16C88-WF25I

Overview

STK16C88-WF25I from Cypress Semiconductor is a 256 Kbit (32K × 8) AutoStore+ nvSRAM with QuantumTrap nonvolatile storage, 25 ns access time, single 5V±10% supply, and industrial temperature range (–40°C to +85°C). It performs automatic STORE on power loss and RECALL on power-up, replacing battery-backed SRAMs in mission-critical data logging and configuration retention systems.

For engineers reviewing the STK16C88-WF25I datasheet, STK16C88-WF25I pinout, STK16C88-WF25I application, or STK16C88-WF25I equivalent, key selection criteria include guaranteed 100-year data retention, 1,000,000 STORE cycles, software-controlled STORE/RECALL via six-address sequence, and hardware protection against low-voltage writes.

Technical Context

The STK16C88-WF25I integrates volatile SRAM and nonvolatile QuantumTrap cells per bit, enabling transparent data persistence without external batteries. Its dual-mode STORE operation-hardware-triggered at V_CC < V_SWITCH (<500 ns latency) and software-initiated via CE-controlled READ sequence-ensures deterministic data capture timing.

RECALL occurs automatically at power-up when V_CC exceeds V_SWITCH (t_HRECALL = 15 ms max), or under software control using identical six-address protocol with final address 0x0C63. Hardware write protection activates when V_CAP < V_SWITCH, blocking inadvertent STORE and SRAM writes during brownout conditions.

Key Specifications

Pinout & Package

28-pin PDIP (600 mil), RoHS-compliant through-hole package with 0.3 inch width, suitable for wave-solder reflow and manual prototyping.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK16C88-WF45I, the -WF25I delivers 25 ns timing for tighter microcontroller integration, while DS1230AB-120+ retains legacy compatibility but introduces battery maintenance, environmental compliance, and finite lifespan trade-offs.

Availability

STK16C88-WF25I is available at Aetrix Electronics and suitable for industrial data loggers, smart energy meters, programmable logic controllers, and medical diagnostic equipment requiring stable component supply and long-term obsolescence support.

Supply support for STK16C88-WF25I 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 belongs to Cypress's AutoStore+ nvSRAM product line, designed specifically to eliminate batteries in SRAM-based data retention applications while maintaining pin-and-code compatibility with legacy battery-backed modules.

FAQ

What triggers automatic STORE on the STK16C88-WF25I?

Automatic STORE initiates when V_CC drops below V_SWITCH (typically ~3.0 V), detected by internal voltage monitor. The operation completes within 500 ns using energy stored in the on-die capacitor. STORE is suppressed unless at least one SRAM write has occurred since the last STORE or RECALL, preventing unnecessary wear.

Can STK16C88-WF25I be used in place of DS1230AB without hardware changes?

Yes - STK16C88-WF25I uses identical 28-pin PDIP packaging, pinout, and DC/AC timing specifications as DS1230AB. No PCB modifications are required. Firmware retains full compatibility, though optional migration to software STORE/RECALL adds robustness beyond basic battery-backup functionality.

How does hardware write protection function during brownout conditions?

When V_CAP falls below V_SWITCH, internal circuitry disables WE and CE path decoding, blocking all SRAM writes and software STORE/RECALL initiation. This prevents partial writes or corrupted data transfer during unstable supply, ensuring memory state integrity even during rapid voltage collapse.

What is the minimum time required between successive software STORE operations?

After initiating software STORE with address 0x0FC0, the device disables I/O for t_STORE (maximum 15 ms). Subsequent accesses must wait until t_STORE completes and outputs return to high-impedance state. No minimum inter-operation delay is required beyond this fixed cycle time - the next STORE may begin immediately upon completion confirmation.