Infineon Technologies STK15C88-SF25TR

Overview

STK15C88-SF25TR from Cypress Semiconductor (now Infineon) is a 8-Kbit (1K × 8) non-volatile static RAM (nvSRAM) with automatic data retention on power loss, integrated lithium battery backup, and industrial temperature range (–40°C to +85°C). It operates at 5 V, supports read/write access times of 25 ns, and retains data for 10 years without external power. It replaces battery-backed SRAM in mission-critical industrial control and metering applications.

For engineers reviewing the STK15C88-SF25TR datasheet, STK15C88-SF25TR pinout, STK15C88-SF25TR application, or STK15C88-SF25TR equivalent, key selection criteria include guaranteed 25 ns access time, embedded Li-ion battery integration, automatic STORE/RECALL operation, and compatibility with standard parallel SRAM interfaces in legacy systems requiring zero-data-loss power failover.

Technical Context

The STK15C88-SF25TR integrates a 8-Kbit SRAM array with an on-die lithium battery and real-time STORE/RECALL controller. Upon V_CC drop below V_TRIP (typically 3.0 V), it autonomously initiates STORE to transfer RAM contents to non-volatile storage within 10 ms.

RECALL occurs automatically at power-up when V_CC exceeds V_TRIP, restoring data in ≤10 ms. The device uses standard asynchronous SRAM timing - no external control logic or firmware is required for data persistence.

Key Specifications

Pinout & Package

STK15C88-SF25TR is housed in a 28-pin Small Outline Integrated Circuit (SOIC-28) package with 300-mil body width and standard gull-wing leads. Pin spacing is 1.27 mm (0.05 inch), compliant with JEDEC MS-012.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK15C88-SF20TR and DS1248W-120+T&R, the STK15C88-SF25TR delivers optimal trade-off between speed, integration, and manufacturability - offering faster access than legacy DIP nvSRAM while avoiding premium cost of 20 ns variants in most industrial timing budgets.

Availability

STK15C88-SF25TR is available at Aetrix Electronics and suitable for smart metering, programmable logic controllers, industrial data loggers, and medical diagnostic equipment requiring stable component supply and long-term data retention assurance.

Supply support for STK15C88-SF25TR 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

Infineon Technologies acquired Cypress Semiconductor in 2020, integrating its nvSRAM, FRAM, and timing portfolio into Infineon's broader memory and embedded solutions business.

This part belongs to the EXCELON™ nvSRAM product line, designed specifically for industrial and automotive applications demanding deterministic, zero-software, hardware-based non-volatility in harsh operating environments.

FAQ

What happens during a rapid power interruption lasting less than 1 ms?

The STK15C88-SF25TR's internal power-fail detector responds to V_CC dips exceeding 10 µs duration. For interruptions under 10 µs, the device remains in normal operation mode and no STORE is triggered. Its 25 ns access time ensures uninterrupted read/write cycles during such brief transients, preserving data coherency without false triggers.

Can STK15C88-SF25TR be used with 3.3 V microcontrollers?

No - STK15C88-SF25TR is strictly a 5 V-only device. Its input thresholds, output drive levels, and internal voltage monitor are calibrated for 5 V operation. Interfacing with 3.3 V logic requires level-shifting circuitry, which introduces timing skew and reliability risks. For 3.3 V systems, consider Infineon's newer SEMPER™ HyperFlash or serial nvSRAM alternatives.

Is the internal lithium battery replaceable or rechargeable?

No - the lithium cell is hermetically sealed inside the SOIC-28 package and not user-serviceable. It is a primary (non-rechargeable) cell with 10-year shelf life at +85°C. There is no charging circuitry; the device draws no current from V_CC to charge the battery. Replacement requires full component swap.

Does STK15C88-SF25TR support write-protection during STORE?

Yes - during STORE execution, the device disables WE# and OE# inputs and places IO0–IO7 in high-impedance state. This prevents external writes or reads from corrupting the transfer process. The STORE sequence is atomic and cannot be interrupted or overridden by host signals, ensuring bit-for-bit data integrity.