Infineon Technologies CY14E256LA-SZ45XQT

Overview

CY14E256LA-SZ45XQT from Infineon Technologies (formerly Cypress) is a 256-Kbit (32 K × 8) nonvolatile static RAM with QuantumTrap technology, functioning as a drop-in SRAM replacement with autonomous power-loss data retention. It delivers 45 ns access time, operates at single 5 V ±10%, supports industrial temperature range (–40°C to +85°C), and uses a 44-pin TSOP II package. It is deployed in industrial PLCs where deterministic STORE/RECALL on brownout ensures I/O state persistence.

For engineers reviewing the CY14E256LA-SZ45XQT datasheet, CY14E256LA-SZ45XQT pinout, CY14E256LA-SZ45XQT application, or CY14E256LA-SZ45XQT equivalent, key selection criteria include AutoStore capacitor sizing (VCAP), HSB timing for hardware-triggered STORE, software STORE address sequence integrity, and compatibility with legacy 5 V SRAM bus interfaces.

Technical Context

The device integrates parallel SRAM and QuantumTrap nonvolatile cells per bit, enabling simultaneous STORE/RECALL across all 32,768 bytes. STORE is triggered automatically on VCC drop below VSWITCH (4.25 V), via HSB pin assertion, or by six-address software sequence; RECALL occurs on power-up or via software command.

During STORE, SRAM write latching prevents spurious triggers - only writes since last STORE/RECALL enable AutoStore or Hardware STORE. The HSB pin serves dual role: open-drain busy indicator (driven LOW during STORE) and active-LOW STORE request input, with internal 100 kΩ pull-up and tHHHD high-pulse after completion.

Key Specifications

Pinout & Package

Package: 44-pin Thin Small-Outline Package (TSOP II), 10.16 mm × 18.41 mm × 1.2 mm, RoHS-compliant, lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with FM24V02-G and MB85RS2MT, CY14E256LA-SZ45XQT uniquely supports 5 V parallel SRAM compatibility, deterministic HSB-controlled STORE, and integrated VCAP management - making it the sole option for retrofitting legacy industrial controllers requiring zero-bus-modification nonvolatility.

Availability

CY14E256LA-SZ45XQT is available at Aetrix Electronics and suitable for industrial PLC I/O modules, smart energy meters, railway signaling controllers, and medical diagnostic equipment requiring stable component supply and long-term lifecycle assurance.

Supply support for CY14E256LA-SZ45XQT 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 is a global semiconductor leader headquartered in Munich, Germany, specializing in power systems, automotive ICs, and industrial control solutions.

CY14E256LA belongs to Infineon's nvSRAM product line, engineered specifically for mission-critical industrial applications where data integrity during power failure is non-negotiable and battery-free reliability is mandatory.

FAQ

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

The CY14E256LA-SZ45XQT requires a 0.1 µF ceramic capacitor on the VCAP pin, placed within 5 mm of the package. This value ensures sufficient stored energy to complete one full STORE cycle even when VCC drops to 4.25 V. Larger capacitors do not improve reliability but may increase power-up time due to charging delay.

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

Yes - the HSB pin may be left floating if hardware STORE triggering and busy indication are unused. The internal 100 kΩ weak pull-up will hold it HIGH during normal operation. However, if the system shares the HSB net with other devices or uses it for diagnostics, a 10 kΩ external pull-up to VCC is recommended for noise immunity.

How does the write-latch mechanism prevent unintended STORE operations?

The CY14E256LA-SZ45XQT implements a write-latch that sets only after at least one SRAM write occurs post-RECALL or post-STORE. AutoStore and Hardware STORE are ignored unless this latch is set - preventing false triggers from noise or power transients. Software STORE bypasses this latch and executes unconditionally.

Is the CY14E256LA-SZ45XQT compatible with standard SRAM timing controllers?

Yes - its 45 ns access time, CE/OE/WE control protocol, and 5 V operation match JEDEC-standard asynchronous SRAM timing. No additional wait-state logic or glue logic is needed. However, the controller must allow for tHRECALL (12 ms) and tSTORE (10 ms) blocking periods during RECALL/STORE, during which all control inputs are ignored.