Infineon Technologies STK11C88-SF45

Overview

STK11C88-SF45 from Cypress Semiconductor is a 256 Kbit (32K × 8) nonvolatile static RAM with QuantumTrap™ technology, functioning as a drop-in replacement for standard SRAMs while retaining data without backup power. It delivers 45 ns access time, operates on a single 5V ±10% supply, and supports automatic hardware RECALL on power-up plus software-initiated STORE/RECALL cycles. Used in industrial control modules where persistent state retention across power cycles is critical.

For engineers reviewing the STK11C88-SF45 datasheet, STK11C88-SF45 pinout, STK11C88-SF45 application, or STK11C88-SF45 equivalent, key selection considerations include its 1,000,000 STORE endurance, 100-year data retention, 28-pin SOIC package compatibility, and software-controlled nonvolatile transfer sequence using six specific CE-controlled read addresses.

Technical Context

The STK11C88 integrates a standard 32K × 8 SRAM array with embedded nonvolatile storage cells per byte, enabling independent SRAM operation and atomic STORE/RECALL transfers. Its dual-mode interface uses standard SRAM control signals (CE, WE, OE) alongside software-defined command sequences-no dedicated command pins required.

STORE and RECALL are initiated exclusively via six consecutive CE-controlled reads to fixed addresses (e.g., 0x0E38 → 0x0FC0 for STORE), with internal state machines managing erase-program (STORE) or clear-restore (RECALL) phases. Hardware RECALL triggers automatically when VCC rises above VSWITCH after brownout or power-on, completing in tHRECALL ≤ 20 ms.

Key Specifications

Pinout & Package

STK11C88-SF45 is housed in a 28-pin Small Outline Integrated Circuit (SOIC) package with 300 mil body width and standard JEDEC MS-012AC dimensions. Pin pitch is 1.27 mm; thermal resistance θJA = 90°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK11C68-SF45 and FM16W08-SO28, STK11C88-SF45 uniquely combines 32K × 8 capacity, 5V operation, automatic power-up RECALL, and proven 1M-store endurance-making it optimal for industrial 5V systems needing full SRAM compatibility and zero-host-restore dependency.

Availability

STK11C88-SF45 is available at Aetrix Electronics and suitable for industrial PLCs, medical infusion pumps, telecom line cards, and automotive body control modules requiring stable component supply and long-term lifecycle support.

Supply support for STK11C88-SF45 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 U.S.-based semiconductor company specializing in memory, microcontrollers, and connectivity solutions for industrial and automotive markets.

The STK11C88 belongs to Cypress's SoftStore® nvSRAM product line, designed specifically to replace battery-backed SRAM and EEPROM in systems demanding instant-on nonvolatility with standard SRAM timing and interface.

FAQ

What is the exact STORE command sequence for STK11C88-SF45?

The STORE command requires six consecutive CE-controlled READ operations to specific addresses in strict order: 0x0E38, 0x31C7, 0x03E0, 0x3C1F, 0x303F, then 0x0FC0. All six must use CE LOW and WE HIGH; OE state is irrelevant. Any interruption aborts the sequence. The chip disables I/O for tSTORE (max 20 ms) before resuming normal operation.

Does STK11C88-SF45 require external components for reliable operation?

Yes-a 0.1 µF ceramic bypass capacitor must be placed between VCC and VSS with minimal trace length to suppress high-frequency noise. A 10 kΩ pull-up resistor from WE to VCC is recommended to prevent accidental writes during power-up. No external battery, capacitor, or controller is needed for nonvolatile functionality.

How does hardware RECALL behave if the device is writing when power is restored?

If a WRITE cycle is active when VCC crosses VSWITCH, the ongoing write may corrupt SRAM contents before RECALL completes. Cypress recommends connecting a 10 kΩ resistor from WE to VCC to force WE HIGH during power ramp, ensuring the device enters a known idle state prior to automatic RECALL initiation.

Is STK11C88-SF45 still recommended for new designs?

No-Cypress explicitly labels STK11C88 as "Not recommended for new designs." It remains in production solely to support existing programs. For new designs, Infineon recommends evaluating newer nvSRAM families like the CY14B108 or FRAM alternatives, though STK11C88-SF45 retains full technical support and supply continuity for legacy systems.