Infineon Technologies STK14CA8-RF25ITR

Overview

STK14CA8-RF25ITR from Cypress Semiconductor is a 1 Mb (128K × 8) nonvolatile static RAM with integrated QuantumTrap storage, operating at 3.0V ±10%, offering 25 ns read access time, automatic STORE on power loss, and automatic RECALL on power-up. It delivers unlimited SRAM read/write endurance while retaining data for 20 years without power, used in industrial control systems requiring persistent memory during brownouts.

For engineers reviewing the STK14CA8-RF25ITR datasheet, STK14CA8-RF25ITR pinout, STK14CA8-RF25ITR application, or STK14CA8-RF25ITR equivalent, key selection criteria include AutoStore timing (12.5 ms), VCAP capacitor requirement (17–120 µF), HSB hardware store-busy signaling, and compatibility with standard SRAM bus protocols in legacy industrial controllers.

Technical Context

The STK14CA8-RF25ITR integrates a 1024×1024 SRAM array with per-cell QuantumTrap nonvolatile storage, enabling atomic STORE/RECALL operations without external controllers. Its dual-cycle architecture supports both hardware-triggered STORE via HSB pin and software-controlled STORE/RECALL using command sequences.

Power-loss detection is handled internally via VSWITCH threshold (2.65 V), initiating AutoStore when VCC drops below this level; RECALL begins automatically upon VCC rising above VSWITCH, completing within 20 ms. The device maintains full SRAM timing compliance (tAVAV = 25 ns) during normal operation while isolating nonvolatile cycles from active memory access.

Key Specifications

Pinout & Package

STK14CA8-RF25ITR is packaged in a 48-pin SSOP (RF package), RoHS-compliant, with 0.5 mm pitch and 10.2 mm × 12.8 mm footprint. Pin assignments are validated per Cypress Document 001-51592 Rev. *A, Page 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK14CA8-RF25ITR, the RF35ITR trades speed for robustness in slow-fail scenarios, while the AS14CA8-25SOT reduces package size and pin count at the cost of hardware-initiated STORE capability and real-time status feedback.

Availability

STK14CA8-RF25ITR is available at Aetrix Electronics and suitable for industrial PLC data logging, medical device configuration storage, and telecom base station control registers requiring stable component supply and long-term lifecycle support.

Supply support for STK14CA8-RF25ITR 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 STK14CA8 product line delivers monolithic nvSRAMs combining SRAM speed with EEPROM-like nonvolatility, targeting applications where battery-free persistence and deterministic STORE/RECALL timing are mandatory.

FAQ

What is the function of the VCAP pin, and what capacitor value is required?

The VCAP pin connects an external capacitor that supplies energy during VCC collapse to complete the AutoStore operation. Cypress specifies 17 µF minimum to 120 µF maximum, rated for 5 V, with low ESR (< 1 Ω). Typical design uses a 47 µF tantalum or polymer capacitor placed adjacent to VCAP and VSS pins to minimize loop inductance.

Can STK14CA8-RF25ITR be used as a drop-in replacement for standard SRAMs?

Yes, it is pin- and cycle-compatible with standard 128K×8 SRAMs in 48-pin SSOP packages, supporting identical address/data/control timing (tAVAV = 25 ns, tRC = 25 ns). However, VCAP must be populated, and HSB should be monitored or left unconnected with its internal weak pull-up active; no firmware changes are needed for basic SRAM operation.

How does the AutoStore operation interact with ongoing SRAM accesses?

AutoStore is initiated only when VCC falls below 2.65 V and halts all SRAM read/write activity until completion (~12.5 ms). During this time, the device ignores E, W, and G inputs, and DQ lines enter high-impedance state. Subsequent accesses resume only after RECALL completes on next power-up.

Is STK14CA8-RF25ITR recommended for new designs?

No - Cypress explicitly marks this part as "Not Recommended for New Designs" in its datasheet (Rev. *A, page 2). While fully functional and supported, Infineon recommends newer nvSRAM families such as the CY14B108 for enhanced reliability, extended temperature range, and improved power-loss immunity in greenfield projects.