Infineon Technologies CY14B108K-ZS25XIT

Overview

CY14B108K-ZS25XIT from Cypress Semiconductor is an 8-Mbit nonvolatile SRAM (nvSRAM) with integrated real-time clock (RTC), organized as 1024 K × 8, featuring 25 ns access time, QuantumTrap nonvolatile storage, and industrial temperature operation (–40°C to +85°C). It combines infinite SRAM read/write cycles with 1 million STORE cycles, 20-year data retention, and supports AutoStore on power-down using a VCAP capacitor.

For engineers reviewing the CY14B108K-ZS25XIT datasheet, CY14B108K-ZS25XIT pinout, CY14B108K-ZS25XIT application, or CY14B108K-ZS25XIT equivalent, key selection considerations include RTC alarm interrupt capability, HSB-controlled hardware STORE, software STORE/RECALL command sequences, and dual backup options (VCAP capacitor or VRTCbat battery).

Technical Context

The device integrates a parallel SRAM array and QuantumTrap nonvolatile elements in a monolithic die, enabling simultaneous STORE/RECALL across all memory cells. Its RTC subsystem includes leap-year tracking, programmable oscillator calibration, and independent alarm/watchdog timer with interrupt output (INT) configurable as active-HIGH push-pull or open-drain.

AutoStore initiates automatically when VCC drops below VSWITCH (~2.0 V), using charge stored on the external VCAP capacitor; the HSB pin provides synchronous hardware STORE control, while software STORE uses address-based command sequences. The RTC operates from either VRTCcap (capacitor-backed) or VRTCbat (battery-backed) supply, with Xin/Xout supporting a 32.768 kHz crystal.

Key Specifications

Pinout & Package

Package: 44-pin Thin Small Outline Package (TSOP II), RoHS-compliant, lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK15C88-3LF35 and DS1248W-120+T&R, CY14B108K-ZS25XIT delivers higher density, faster access, integrated alarm/watchdog, and superior nonvolatile reliability-making it optimal for new industrial and medical designs requiring robust timestamped data persistence.

Availability

CY14B108K-ZS25XIT is available at Aetrix Electronics and suitable for industrial data loggers, smart energy meters, PLC controller modules, and medical diagnostic equipment requiring stable component supply, long-term lifecycle support, and guaranteed RoHS compliance.

Supply support for CY14B108K-ZS25XIT 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 fabless semiconductor company specializing in embedded systems solutions, including PSoC, USB, memory, and timing products.

This part belongs to Cypress's nvSRAM product line, designed specifically for applications demanding zero-data-loss memory persistence alongside accurate, autonomous timekeeping under variable power conditions.

FAQ

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

The datasheet specifies a minimum 47 µF tantalum or electrolytic capacitor on VCAP for full AutoStore functionality at –40°C to +85°C. Lower values may work at room temperature but risk incomplete STORE under worst-case voltage droop and temperature extremes. Use low-ESR capacitors rated for ≥10 V to ensure sufficient charge delivery during VCC collapse.

Can the RTC operate independently while the SRAM is being accessed?

Yes-the RTC runs autonomously from the SRAM array using its dedicated oscillator and backup supply (VCAP or VRTCbat). Reads/writes to SRAM do not stall or interfere with RTC timekeeping, alarm generation, or watchdog counting. Both subsystems operate concurrently with no arbitration overhead.

Is CY14B108K-ZS25XIT pin-compatible with CY14B108M variants?

No-CY14B108K (×8) and CY14B108M (×16) differ in address/data pin mapping: K uses A0–A19 and DQ0–DQ7; M uses A0–A18 and DQ0–DQ15 with BHE/BLE. They share the same 44-pin TSOP II footprint but require distinct PCB layouts and firmware addressing schemes.

Does the AutoStore Disable feature function reliably in this revision?

No-the datasheet errata (Rev. *N, page 33) explicitly states that the AutoStore Disable feature does not work. Any attempt to disable AutoStore via software sequence will fail. To prevent unintended STOREs, omit the VCAP capacitor and use only software or HSB-triggered STORE operations in designs where automatic power-loss saving is undesirable.