Infineon Technologies CY14B256L-SP35XC

Overview

CY14B256L-SP35XC from Cypress Semiconductor is a 256 Kbit (32K × 8) nonvolatile SRAM with QuantumTrap™ technology, functioning as a drop-in SRAM replacement with integrated nonvolatile storage. It delivers 35 ns access time, operates from single 3V ±10% supply, supports AutoStore™ on power loss via VCAP capacitor, and enables software/hardware STORE/RECALL. Used in industrial control modules requiring persistent memory retention during unexpected power failure.

For engineers reviewing the CY14B256L-SP35XC datasheet, CY14B256L-SP35XC pinout, CY14B256L-SP35XC application, or CY14B256L-SP35XC equivalent, key selection criteria include STORE cycle endurance (200,000 cycles), data retention (20 years at 55°C), VCAP-based AutoStore timing, HSB-controlled hardware store arbitration, and compatibility with STK14D88 footprint.

Technical Context

The CY14B256L-SP35XC integrates a standard fast SRAM array (512 × 512) with parallel QuantumTrap nonvolatile cells per bit, enabling simultaneous STORE/RECALL across all 32,768 bytes. Its architecture decouples volatile read/write performance from nonvolatile persistence-SRAM supports unlimited cycles while QuantumTrap guarantees 200,000 STOREs and 20-year retention at 55°C.

STORE is triggered by three independent mechanisms: AutoStore on VCC drop below VSWITCH (using charge from VCAP), hardware STORE via HSB pin assertion, or software STORE via six-address CE-controlled READ sequence (0x0E38 → 0x0FC0). RECALL occurs automatically on power-up or via identical six-address sequence ending at 0x0C63, with tHRECALL = 15 ms typical.

Key Specifications

Pinout & Package

Package: 32-pin SOIC (300 mil width), RoHS-compliant, surface-mountable with standard reflow profile.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK14D88-35I, CY14B256L-SP35XC adds HSB-driven hardware STORE coordination and higher STORE endurance; compared with FM24V02-G, it offers parallel bus speed and deterministic STORE timing but requires more PCB area and VCAP support.

Availability

CY14B256L-SP35XC is available at Aetrix Electronics and suitable for industrial PLC data logging, medical device parameter backup, and telecom base station configuration requiring stable component supply and long-term lifecycle assurance.

Supply support for CY14B256L-SP35XC 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 CY14B series targets applications needing SRAM-speed access with guaranteed nonvolatile retention - specifically engineered for systems where battery backup is impractical and EEPROM write latency is unacceptable.

FAQ

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

The CY14B256L-SP35XC requires a minimum 4.7 µF tantalum capacitor on the VCAP pin, rated for ≥6.3V, with ESR ≤ 1 Ω. This value ensures sufficient charge to complete a full STORE cycle when VCC drops below 2.7V. Ceramic capacitors are not recommended due to insufficient capacitance stability under bias and temperature.

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

Yes - the HSB pin has an internal weak pull-up and may be left floating if hardware STORE initiation and busy monitoring are not required. Leaving it unconnected does not affect AutoStore or software STORE functionality, nor does it impact power consumption or timing behavior during normal SRAM operation.

How does the CY14B256L-SP35XC handle partial STORE operations during power interruption?

The device guarantees atomic STORE: either the entire 32K × 8 array is saved or none is. If VCAP voltage falls below operational threshold mid-STORE, the cycle aborts and SRAM contents remain intact. No partial or corrupted nonvolatile writes occur - the QuantumTrap cell design enforces all-or-nothing programming at the full-array level.

Is the CY14B256L-SP35XC compatible with 5V-tolerant microcontrollers?

No - the CY14B256L-SP35XC is strictly a 3V-only device (3.0V–3.6V). Its inputs are not 5V-tolerant; connecting to a 5V bus without level translation will exceed absolute maximum ratings and cause permanent damage. Interface requires dedicated 3.3V logic or bidirectional voltage translators such as TXS0108E.