Infineon Technologies CY14E256L-SZ45XCT

Overview

CY14E256L-SZ45XCT from Cypress Semiconductor is a 256 Kbit (32K × 8) nonvolatile SRAM with QuantumTrap technology, operating at 45 ns access time, single 5V ±10% supply, and housed in a 32-pin SOIC package. It performs automatic STORE on power-down using an external 68 µF capacitor on VCAP, supports software/hardware STORE/RECALL, and delivers 100-year data retention with 1 million STORE cycles - deployed in industrial control loggers requiring persistent memory without battery backup.

For engineers reviewing the CY14E256L-SZ45XCT datasheet, CY14E256L-SZ45XCT pinout, CY14E256L-SZ45XCT application, or CY14E256L-SZ45XCT equivalent, key selection criteria include AutoStore timing under voltage droop, HSB-driven hardware store latency, VCAP capacitor sizing for reliable STORE completion, and software address sequence integrity for deterministic nonvolatile write initiation.

Technical Context

The CY14E256L integrates standard SRAM array (512 × 512) with parallel QuantumTrap nonvolatile cells per bit, enabling simultaneous STORE/RECALL across all 32,768 bytes. STORE is triggered by power loss (VCC < VSWITCH), HSB assertion, or six-step CE-controlled READ sequence; RECALL occurs automatically at power-up or via identical six-step sequence ending at 0x0C63.

During STORE, SRAM read/write is inhibited for tSTORE (max 10 ms); during RECALL, SRAM is cleared then loaded, taking tRECALL (max 10 ms). The HSB pin serves dual role: open-drain busy indicator (driven LOW during STORE) and active-LOW hardware trigger, with internal pull-up and tDELAY timing to complete pending writes before initiation.

Key Specifications

Pinout & Package

Package: 32-pin Small Outline Integrated Circuit (SOIC), RoHS-compliant, 300-mil body width, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK14C88-45I and FM24V10-G, CY14E256L-SZ45XCT uniquely balances 5V compatibility, 45 ns speed, 100-year retention, and capacitor-based AutoStore - making it optimal for retrofitting legacy 5V industrial controllers where battery-free persistence is critical but F-RAM migration is impractical.

Availability

CY14E256L-SZ45XCT is available at Aetrix Electronics and suitable for industrial data loggers, POS terminal transaction buffers, and PLC state memory requiring stable component supply with long-term lifecycle assurance.

Supply support for CY14E256L-SZ45XCT 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) designs high-reliability memory and programmable solutions for industrial, automotive, and communications markets.

The CY14E series targets applications demanding battery-free nonvolatility in standard SRAM footprints, specifically optimizing QuantumTrap nvSRAM for deterministic power-loss data capture in mission-critical embedded systems.

FAQ

What is the minimum VCAP capacitance required for reliable AutoStore operation?

The CY14E256L-SZ45XCT requires a minimum 68 µF capacitor on VCAP, rated at 6V with ±20% tolerance. This value ensures sufficient stored energy to complete the full 10 ms STORE cycle when VCC drops below VSWITCH (≈3.6V). Using less capacitance risks incomplete STORE and data loss; values up to 220 µF are supported for extended hold time.

Can the HSB pin be left unconnected if hardware STORE is not used?

Yes - the HSB pin has an internal weak pull-up resistor and may be left floating if hardware STORE is not implemented. However, leaving it unconnected forfeits real-time STORE progress indication. For status monitoring, connect a 10 kΩ pull-up to VCAP and poll HSB LOW-to-HIGH transition to detect STORE completion.

How does the CY14E256L prevent STORE corruption during partial writes?

The device inhibits AutoStore and Hardware STORE unless at least one valid WRITE operation has occurred since the last STORE or RECALL. This WRITE-gating logic ensures nonvolatile storage is only triggered after actual data modification, preventing unnecessary QuantumTrap wear and avoiding spurious saves during idle periods or initialization.

Is the software STORE sequence compatible with standard SRAM read timing?

Yes - the six-address software STORE sequence uses standard CE-controlled READ cycles with no special timing constraints beyond tAA (45 ns) and tACE. Each address must be accessed sequentially with CE LOW and OE HIGH or LOW; intervening writes or address changes abort the sequence. No additional wait states or bus protocols are required.