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Cypress Semiconductor Corp CY14B256I-SFXIT
- Part No.:
- CY14B256I-SFXIT
- Manufacturer:
- Cypress Semiconductor Corp
- Category:
- Memory
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
CY14B256I-SFXIT.pdf
- Description:
- IC NVSRAM 256KBIT I2C 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:896
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Product details
Overview
CY14B256I-SFXIT from Infineon Technologies (formerly Cypress) is a 256-Kbit (32 K × 8) serial I²C nonvolatile SRAM with integrated real-time clock, operating at 2.7–3.6 V, supporting I²C speeds up to 3.4 MHz, and featuring AutoStore on power-loss using an external capacitor. It delivers infinite SRAM read/write cycles, 1 million STORE cycles to QuantumTrap nonvolatile elements, and 20-year data retention at 85 °C - deployed in industrial metering, PLCs, and backup-critical control systems.
For engineers reviewing the CY14B256I-SFXIT datasheet, CY14B256I-SFXIT pinout, CY14B256I-SFXIT application, or CY14B256I-SFXIT equivalent, key selection considerations include I²C speed mode support (100 kHz/400 kHz/1 MHz/3.4 MHz), RTC alarm and watchdog interrupt capability, hardware STORE/RECALL via HSB pin, VCAP-backed AutoStore timing, and dual RTC backup options (capacitor or battery).
Technical Context
This device integrates two independent functional blocks: a 32 K × 8 nvSRAM core with QuantumTrap nonvolatile storage and a full-featured RTC subsystem with programmable square-wave output (1 Hz / 512 Hz / 4.096 kHz / 32.768 kHz), alarm, watchdog timer, and power-fail monitoring. The memory and RTC share a unified I²C slave interface but maintain separate register maps and control logic.
STORE operations occur automatically on VCC drop below threshold (using charge stored on VCAP), or manually via Software STORE command or HSB pin assertion; RECALL occurs on power-up or via Software RECALL. RTC operation continues during VCC brownout when backed by VRTCcap or VRTCbat, drawing only 0.45 µA typical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory density | 256 Kbit (32 K × 8) - supports byte-level random access without refresh, ideal for parameter logging and state retention. |
| I²C interface speed | Up to 3.4 MHz (High Speed mode) - enables sub-100 µs write bursts, reducing firmware latency in time-critical control loops. |
| RTC backup current | 0.45 µA typical - allows >1 year runtime on a 0.1 F supercapacitor, eliminating battery replacement in sealed enclosures. |
| Data retention | 20 years at 85 °C - validated for long-life deployment in industrial environments without periodic recalibration or data reload. |
| STORE endurance | 1 million cycles to QuantumTrap - exceeds typical field lifetime requirements for daily power-cycle applications like smart meters. |
| Operating voltage | 2.7 V to 3.6 V - compatible with standard 3.3 V logic rails and tolerant of wide input variation in unregulated power domains. |
| Temperature range | –40 °C to +85 °C - qualified for extended industrial temperature operation without derating. |
Pinout & Package
Package: 16-pin SOIC (Small Outline Integrated Circuit), RoHS-compliant, body width 3.9 mm, lead pitch 1.27 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC | Power supply input | Primary 2.7–3.6 V supply for nvSRAM and RTC logic; powers internal regulators for VRTCcap/VRTCbat circuitry. |
| VSS | Ground reference | Common return path for all digital and analog functions; must be low-impedance for RTC accuracy and STORE reliability. |
| SCL | I²C clock input | Master-generated clock up to 3.4 MHz; open-drain requires external pull-up; timing critical for STORE/RECALL command execution. |
| SDA | I²C bidirectional data | Open-drain I/O shared between memory and RTC registers; requires external pull-up; supports ACK/NACK handshaking per byte. |
| WP | Hardware write protect | Active-low enable: pulls LOW to lock entire memory array; internally pulled down - can be left floating if unused. |
| A0–A2 | I²C slave address inputs | Set 3-bit LSB of 7-bit slave address (base 0x50); internally pulled LOW - default address 0x50 when all unconnected. |
| HSB | Hardware STORE busy | Open-drain status output (LOW = busy); also accepts active-LOW trigger for manual STORE; requires pull-up for reliable detection. |
| VCAP | AutoStore energy reservoir | Connects to external capacitor (typically 0.1–0.47 F); supplies hold-up power during VCC collapse to complete STORE within ~20 ms. |
| INT/SQW | RTC interrupt/square wave | Programmable dual-function pin: generates alarm/watchdog interrupts or outputs precise square waves at four selectable frequencies. |
| VRTCcap | RTC capacitor backup | Input for optional supercapacitor backup; used instead of VRTCbat; enables maintenance-free RTC operation in battery-prohibited zones. |
| VRTCbat | RTC battery backup | Input for coin-cell battery (e.g., CR2032); used instead of VRTCcap; provides >10-year RTC uptime with low-leakage design. |
| Xin / Xout | RTC crystal oscillator | Connects to 32.768 kHz tuning-fork crystal; forms precision timebase; requires load capacitance matching per crystal spec. |
| NC | No connect | Internally unconnected; must remain floating - no routing or termination required. |
Key Features
| Feature | Design Value |
|---|---|
| AutoStore on power-loss | Guarantees data persistence without firmware intervention using VCAP charge - eliminates risk of corrupted state after unexpected shutdown. |
| Power-Up RECALL | Restores full 32 K × 8 memory image within 10 ms of VCC stabilization - enables deterministic boot behavior in embedded controllers. |
| RTC with alarm & watchdog | Enables time-triggered events (e.g., scheduled calibration) and system health monitoring (e.g., task timeout detection) in a single chip. |
| Four-speed I²C support | Operates across standard (100 kHz), fast (400 kHz), fast-plus (1 MHz), and high-speed (3.4 MHz) modes - simplifies migration across host platforms. |
| Software block protection | Allows selective locking of ¼, ½, or full memory array via I²C commands - prevents accidental overwrites of critical configuration sectors. |
Applications
| Industrial Energy Metering | Programmable Logic Controllers (PLCs) |
|---|---|
Use Scenario: Storing tariff schedules, accumulated kWh readings, and event logs across frequent power interruptions in utility-grade meters. IC Role / Device Role / Timing Role: Nonvolatile memory + time-stamping engine - retains billing data and timestamps each outage/resume cycle via RTC. Use Value: Eliminates external FRAM + RTC ICs; meets IEC 62056 compliance for tamper-proof, time-synchronized energy data retention. | Use Scenario: Preserving ladder logic state, I/O mapping, and diagnostic history during controller reboot or main power loss in factory automation. IC Role / Device Role / Timing Role: State-holding memory + deterministic boot timer - ensures consistent scan cycle timing and fault recovery sequence. Use Value: Reduces BOM count by integrating memory persistence and timekeeping, enabling compact DIN-rail controller designs with <50 ms restart latency. |
| Medical Infusion Pumps | Smart Grid Remote Terminals (RTUs) |
Use Scenario: Logging drug delivery parameters, error codes, and operator actions for FDA audit trails, with guaranteed integrity during battery swaps or AC dropout. IC Role / Device Role / Timing Role: Secure nonvolatile log buffer + calibrated RTC - timestamps every dose event and records power-fail occurrences. Use Value: Meets IEC 62304 software safety requirements by ensuring traceable, time-stamped operational history without volatile cache dependency. | Use Scenario: Maintaining SCADA configuration, telemetry buffers, and time-synced event records in outdoor substations subject to lightning-induced outages. IC Role / Device Role / Timing Role: Fault-tolerant memory + IEEE 1588-compatible time source - synchronizes packet timestamps and stores grid disturbance waveforms. Use Value: Enables Class 1 power quality monitoring (IEC 61000-4-30) with sub-second timestamp accuracy and zero data loss during 100-ms brownouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar nvSRAM+RTC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STK14CA8-NF50I | Parallel interface (not I²C); 256 Kbit nvSRAM only - no integrated RTC; requires external oscillator and interrupt controller. | Suitable for legacy microcontrollers with parallel bus but no I²C; adds board area and complexity for timekeeping. | Select only when existing hardware lacks I²C or demands faster random-access throughput (>10 MB/s). |
| DS1347Z+ | Standalone RTC with trickle-charge controller; no memory - requires external EEPROM/FRAM for data storage. | Used where RTC accuracy (<2 ppm) or battery-swappable design is prioritized over memory integration. | Choose when long-term RTC drift tolerance is <±2 ppm/year and memory size exceeds 256 Kbit or requires different endurance specs. |
Compared with STK14CA8-NF50I and DS1347Z+, CY14B256I-SFXIT uniquely combines I²C-addressable nvSRAM and full-featured RTC in one SOIC package - reducing interconnect count, PCB footprint, and firmware overhead for time-stamped data logging.
Availability
CY14B256I-SFXIT is available at Aetrix Electronics and suitable for industrial energy metering, programmable logic controllers, medical infusion pumps, and smart grid remote terminals requiring stable component supply, long-term data integrity, and precise time synchronization.
Supply support for CY14B256I-SFXIT 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, delivering power systems, sensors, and microcontrollers for industrial, automotive, and IoT applications.
CY14B256I belongs to Infineon's legacy Cypress nvSRAM product line, engineered specifically for systems demanding simultaneous nonvolatile data retention and autonomous timekeeping without external support components.
FAQ
What is the minimum VCAP capacitance required for reliable AutoStore operation?
The datasheet specifies a minimum VCAP value of 0.1 F for guaranteed STORE completion under worst-case conditions (VCC = 2.7 V, T = 85 °C). Using 0.22 F or 0.47 F improves margin against capacitor aging and ESR increase over time. The VCAP pin must never be shorted to ground or connected to regulated voltage - it serves solely as an energy reservoir during power collapse.
Can the RTC operate independently while the nvSRAM is held in reset or powered down?
Yes - the RTC continues running as long as either VRTCcap or VRTCbat is present and valid, even if VCC is removed or held below operating threshold. The RTC maintains time, alarms, and watchdog functions autonomously, drawing only 0.45 µA typical from the backup source. Memory access is disabled during VCC absence, but RTC registers remain readable via I²C when VCC is restored.
How does the HSB pin behave during a Hardware STORE initiated by pulling it LOW?
When HSB is pulled LOW externally, the device initiates STORE immediately and drives HSB LOW until completion (tHHHD ≈ 20 ms max). Upon finish, HSB transitions HIGH for ~10 µs with strong drive, then reverts to weak internal pull-up. An external 10 kΩ pull-up is recommended to ensure clean edge detection in noisy industrial environments.
Is the 8-byte serial number writable and lockable, and what is its factory default state?
Yes - the 8-byte serial number is user-writable via I²C command and can be permanently locked using a dedicated lock bit. Factory default values are all 0xFF; once locked, the serial number becomes read-only and immune to further writes. This enables secure device identification and anti-counterfeiting in certified industrial deployments.
CY14B256I-SFXIT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Cypress Semiconductor Corp
- Series:
- -
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- NVSRAM
- Technology:
- NVSRAM (Non-Volatile SRAM)
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- I2C
- Clock Frequency:
- 3.4 MHz
- Write Cycle Time - Word, Page:
- -
- Access Time:
- -
- Voltage - Supply:
- 2.7V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
CY14B256I-SFXIT FAQ
1.How can I place an order for CY14B256I-SFXIT through Aetrix?
Please submit a Request for Quotation (RFQ) for CY14B256I-SFXIT on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for CY14B256I-SFXIT reliable?
The price and inventory of CY14B256I-SFXIT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CY14B256I-SFXIT is usually 5 days.
3.What payment methods are accepted for CY14B256I-SFXIT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CY14B256I-SFXIT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CY14B256I-SFXIT?
CY14B256I-SFXIT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CY14B256I-SFXIT order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for CY14B256I-SFXIT?
For technical support, including CY14B256I-SFXIT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CY14B256I-SFXIT requirements.
6.How does Aetrix verify that CY14B256I-SFXIT is sourced from the original manufacturer or authorized distributors?
All CY14B256I-SFXIT products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that CY14B256I-SFXIT meets industry standards.
7.What is the process for return or replacement of CY14B256I-SFXIT?
All CY14B256I-SFXIT units undergo pre-shipment inspection (PSI). If there is an issue with CY14B256I-SFXIT, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The CY14B256I-SFXIT part is unused and in its original packaging.
Return procedure for CY14B256I-SFXIT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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