Infineon Technologies CY14B108K-ZS45XIT

Overview

CY14B108K-ZS45XIT from Cypress Semiconductor is an 8-Mbit nonvolatile SRAM (nvSRAM) with integrated real-time clock (RTC), organized as 1024 K × 8, featuring 45 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-ZS45XIT datasheet, CY14B108K-ZS45XIT pinout, CY14B108K-ZS45XIT application, or CY14B108K-ZS45XIT equivalent, key selection criteria include RTC alarm programmability, watchdog timer integration, VRTCcap/VRTCbat dual backup support, HSB-controlled hardware STORE, and TSOP II 44-pin compatibility in embedded systems requiring deterministic nonvolatile memory persistence without battery replacement.

Technical Context

The device integrates a standard SRAM array with parallel-connected QuantumTrap nonvolatile elements, enabling simultaneous STORE/RECALL across all cells. Its RTC includes leap-year tracking, programmable oscillator calibration, and interrupt-driven alarm/wdog functions-all operating independently of SRAM access.

AutoStore initiates when VCC drops below VSWITCH (~2.7 V), switching power source from VCC to the external VCAP capacitor to complete one full STORE cycle. The HSB pin serves dual role: input for hardware-triggered STORE and open-drain output indicating STORE busy status via active-low assertion.

Key Specifications

Pinout & Package

Package: 44-pin Thin Small Outline Package (TSOP II), Type 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 STK14CA8-NL35I and FM24V10-G, CY14B108K-ZS45XIT uniquely delivers monolithic 8-Mbit nvSRAM + full-featured RTC in one TSOP package, enabling compact, low-BOM-count designs for time-stamped industrial logging where deterministic STORE timing and calendar accuracy are mandatory.

Availability

CY14B108K-ZS45XIT is available at Aetrix Electronics and suitable for industrial PLC data logging, smart meter time-stamped events, and railway signaling event recorders requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for CY14B108K-ZS45XIT 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 high-reliability memory, microcontrollers, and connectivity solutions for industrial, automotive, and IoT markets.

CY14B108K belongs to Cypress's nvSRAM product line, designed specifically for mission-critical applications demanding guaranteed data persistence during power loss without battery maintenance or complex firmware handling.

FAQ

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

The CY14B108K-ZS45XIT requires a minimum 12 µF tantalum capacitor on the VCAP pin, rated for ≥6.3 V, with ESR ≤ 1 Ω. This value ensures sufficient energy to complete one full STORE cycle when VCC drops from 3.0 V to VSWITCH (2.7 V) within the specified tSTORE timing. Ceramic capacitors are not recommended due to insufficient charge capacity and voltage coefficient effects.

Can the RTC operate independently while the nvSRAM is undergoing STORE or RECALL?

Yes-the RTC runs continuously from its dedicated backup supply (VRTCcap or VRTCbat) and is fully independent of SRAM operations. During STORE/RECALL, the RTC maintains timekeeping, alarm scheduling, and oscillator calibration without interruption or timing drift, as confirmed in Section 10 of the datasheet (RTC Operation).

Is the HSB pin compatible with 1.8 V logic systems?

No-HSB is a 3.0 V domain I/O. Its input threshold is referenced to VCC (2.0 V typical VIH), and its open-drain output pulls to VCC. Direct connection to 1.8 V GPIO requires level translation; driving HSB LOW with a 1.8 V signal may fail to meet VIH/VIL thresholds and cause unreliable STORE triggering.

Does the CY14B108K-ZS45XIT support software STORE without prior write activity?

Yes-unlike AutoStore and Hardware STORE, which require at least one SRAM write since last STORE/RECALL, Software STORE (initiated via specific address sequence) executes unconditionally. This enables forced persistence for critical state snapshots regardless of recent memory activity, as documented in Section 7 of the datasheet.