Infineon Technologies CY14B256LA-SZ25XI

Overview

CY14B256LA-SZ25XI 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 25 ns access time, operates from 2.7 V to 3.6 V, supports industrial temperature range (–40 °C to +85 °C), and integrates AutoStore via external VCAP capacitor for hands-off STORE on power-down - deployed in industrial PLCs, medical data loggers, and metering systems requiring persistent memory without backup batteries.

For engineers reviewing the CY14B256LA-SZ25XI datasheet, CY14B256LA-SZ25XI pinout, CY14B256LA-SZ25XI application, or CY14B256LA-SZ25XI equivalent, key selection considerations include VCAP capacitor sizing (0.1 µF), HSB pin timing for hardware STORE acknowledgment, software STORE address sequence (0x0E38 → 0x31C7 → 0x03E0), and compatibility with standard 32-pin SOIC footprint and 3.3 V logic interfaces.

Technical Context

The CY14B256LA-SZ25XI embeds parallel SRAM and QuantumTrap nonvolatile cells per bit, enabling simultaneous STORE/RECALL across all 32,768 bytes. Its architecture decouples volatile read/write (infinite cycles) from nonvolatile endurance (1 million STOREs, 20-year retention), with STORE triggered by power loss, HSB assertion, or software sequence - all inhibiting SRAM access during transfer.

AutoStore relies on regulated charge transfer from VCAP (0.1 µF ceramic) when VCC drops below VSWITCH (2.2 V typ.), while RECALL at power-up restores full SRAM contents in ≤20 ms. The device uses standard SRAM control protocol (CE/OE/WE), with HSB serving dual role: open-drain busy indicator and hardware STORE initiator with tDELAY = 100 ns min.

Key Specifications

Pinout & Package

Package: 32-pin Small Outline Integrated Circuit (SOIC), 300 mil width, RoHS-compliant, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with FM24V10-G and MB85RS2MT, CY14B256LA-SZ25XI uniquely combines parallel SRAM pinout, hardware STORE/RECALL signaling (HSB), and capacitor-based AutoStore - making it the only option for drop-in replacement of legacy SRAMs in safety-critical industrial controllers requiring zero firmware modification.

Availability

CY14B256LA-SZ25XI is available at Aetrix Electronics and suitable for industrial PLCs, smart electricity meters, medical diagnostic loggers, and railway signaling units requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for CY14B256LA-SZ25XI 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 management, automotive MCUs, and memory solutions for industrial and mission-critical applications.

CY14B256LA belongs to Infineon's nvSRAM product line, engineered specifically to replace battery-backed SRAM in industrial automation, energy metering, and medical devices - eliminating maintenance, leakage, and environmental compliance risks.

FAQ

What is the minimum VCAP capacitor value required for reliable AutoStore operation?

The CY14B256LA-SZ25XI requires a 0.1 µF ±20% X7R ceramic capacitor connected between VCAP and VSS. This value ensures sufficient charge storage to complete one full STORE cycle when VCC drops from 3.0 V to 2.2 V within 100 µs. Using smaller capacitors risks incomplete STORE and data corruption; larger values do not improve reliability but may slow power-up timing.

Can CY14B256LA-SZ25XI be used as a direct replacement for standard 32K×8 SRAMs?

Yes - it is pin-compatible with industry-standard 32-pin SOIC 32K×8 SRAMs (e.g., IS61LV256AL) and uses identical CE/OE/WE control timing. No address or data bus changes are needed. However, VCAP must be populated and HSB should be monitored or left unconnected; OE must remain HIGH during writes to avoid bus contention.

How does the software STORE sequence prevent accidental activation?

The software STORE requires three consecutive, uninterrupted read operations from exact addresses (0x0E38, then 0x31C7, then 0x03E0) with no intervening writes or address changes. Any deviation - including bus glitches, cache misses, or debugger interrupts - aborts the sequence. This design ensures STORE is never triggered unintentionally during normal SRAM read activity.

What happens if the HSB pin is left floating during operation?

Leaving HSB unconnected is safe and recommended if hardware STORE is not used. The internal 100 kΩ weak pull-up holds HSB HIGH during idle periods. During STORE/RECALL, the pin is actively driven LOW. Floating HSB introduces no risk of false triggering, but monitoring it externally enables precise timing control for MPU synchronization in deterministic real-time systems.