Infineon Technologies STK11C68-SF35TR

Overview

STK11C68-SF35TR from STMicroelectronics is a non-volatile static RAM (nvSRAM) with 8-Kbit capacity, 5V supply voltage, and automatic STORE/RECALL functionality triggered by power loss. It features 100,000 STORE cycles, 10-year data retention without battery, and operates across industrial temperature range (–40°C to +85°C). It serves as a drop-in replacement for battery-backed SRAM in metering and industrial control systems requiring deterministic non-volatility.

For engineers reviewing the STK11C68-SF35TR datasheet, STK11C68-SF35TR pinout, STK11C68-SF35TR application, or STK11C68-SF35TR equivalent, key selection criteria include STORE cycle endurance, zero-battery architecture, industrial temperature support, and compatibility with standard SRAM timing interfaces.

Technical Context

The STK11C68-SF35TR integrates an 8-Kbit SRAM array with on-chip EEPROM storage and autonomous power-fail detection circuitry. Its STORE operation transfers SRAM contents to EEPROM within 10 ms upon V_CC drop below 3.6 V, while RECALL restores data on power-up in ≤15 ms.

It uses standard parallel SRAM interface timing (t_AA = 35 ns, t_OE = 25 ns), supports asynchronous read/write, and requires no external components for non-volatile operation - eliminating battery maintenance, leakage, and environmental disposal concerns.

Key Specifications

Pinout & Package

STK11C68-SF35TR is housed in a 28-pin SOIC package (300 mil width) with standard parallel SRAM pinout and integrated power-fail detection logic.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK11C68-SF35TR, the STK11C68-SF35T offers identical functionality in tape-and-reel form for automated assembly, while DS1230Y-100+ relies on external battery backup - introducing maintenance, leakage, and end-of-life replacement risks absent in the STMicroelectronics solution.

Availability

STK11C68-SF35TR is available at Aetrix Electronics and suitable for smart metering, industrial PLC data logging, and medical device configuration storage requiring stable component supply and long-lifecycle assurance.

Supply support for STK11C68-SF35TR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering intelligent power, sensing, and control solutions across automotive, industrial, and consumer markets.

The STK11C68 belongs to ST's nvSRAM product line, engineered specifically to replace battery-backed SRAM in mission-critical industrial and metering applications where reliability, longevity, and maintenance-free operation are mandatory.

FAQ

What is the STORE latency of STK11C68-SF35TR during power failure?

The STK11C68-SF35TR initiates STORE automatically when V_CC falls below 3.6 V, completing the SRAM-to-EEPROM transfer in ≤10 ms. This is guaranteed across the full industrial temperature range and requires no host processor involvement or external circuitry.

Can STK11C68-SF35TR be used as a direct replacement for standard 6264 SRAM?

Yes - it uses identical pinout, timing (35 ns access), and control signals (CE#, OE#, WE#). No hardware or firmware changes are needed beyond removing the backup battery and associated circuitry, making it a true drop-in upgrade path.

Does STK11C68-SF35TR support WRITE protection during STORE/RECALL?

During STORE or RECALL, the device places I/O pins in high-impedance state and ignores CE#, OE#, and WE# inputs. This prevents bus contention and ensures data integrity - no external hardware lockout is required.

How is data integrity verified after RECALL operation?

RECALL is a hardware-controlled, atomic operation with built-in error checking. The device asserts READY# low until EEPROM-to-SRAM transfer completes successfully; no CRC or checksum is exposed to the host, as correctness is ensured by internal state machines and redundancy.