Infineon Technologies CY15B104QN-20BFXIT

Overview

CY15B104QN-20BFXIT from Infineon is a 4-Mb serial ferroelectric RAM (F-RAM) organized as 512K × 8, operating over SPI at up to 50 MHz with 1.8 V–3.6 V supply, 10¹⁵ write endurance, and 151-year data retention. It serves as a nonvolatile memory replacement for EEPROM/flash in high-write-cycle industrial logging and sensor data buffering.

For engineers reviewing the CY15B104QN-20BFXIT datasheet, CY15B104QN-20BFXIT pinout, CY15B104QN-20BFXIT application, or CY15B104QN-20BFXIT equivalent, this device delivers instant nonvolatile writes, zero write latency, hardware/software write protection, and industrial temperature support (–40°C to +85°C) without polling or page programming overhead.

Technical Context

The CY15B104QN-20BFXIT implements an SPI slave interface compliant with modes 0 and 3, supporting full-duplex communication with SI/SO pins and chip-select–driven activation. Its internal architecture includes a 512K × 8 F-RAM array, a dedicated 256-byte special sector, nonvolatile status register, Device ID, and 8-byte writable serial number registers.

Write operations complete at bus speed-no delay between byte transfers-and are enabled only after Write Enable (WREN) instruction and valid CS assertion. The WP pin provides hardware-level protection for status register writes when WPEN = 1, while software block protection supports 1/4, 1/2, or full-array locking.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (Small Outline Integrated Circuit), RoHS-compliant, surface-mount, standard footprint compatible with automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY15B104QN-20LPXIT and FM25V04-G, the CY15B104QN-20BFXIT uniquely combines SOIC manufacturability, full industrial temp rating, special-sector reflow resilience, and factory-assigned serial identity - making it optimal for high-reliability, field-deployed industrial electronics.

Availability

CY15B104QN-20BFXIT is available at Aetrix Electronics and suitable for industrial data loggers, smart meter firmware storage, and PLC I/O module configuration requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for CY15B104QN-20BFXIT 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 German semiconductor leader specializing in power management, sensing, and nonvolatile memory solutions for industrial, automotive, and IoT markets.

The EXCELON™ LP F-RAM product line targets high-reliability, high-write-frequency applications where flash and EEPROM fail - delivering instant writes, extreme endurance, and deterministic timing for mission-critical embedded systems.

FAQ

Is CY15B104QN-20BFXIT pin-compatible with standard SPI EEPROMs like AT25DF041A?

Yes - it uses identical 8-pin SOIC pinout (CS, SCK, SI, SO, WP, VSS, VDD, DNU) and SPI command set subsets, allowing drop-in replacement in most existing layouts. However, WP behavior differs: CY15B104QN requires WPEN bit set in status register to activate hardware protection, whereas AT25DF041A uses WP as unconditional lock. Firmware must initialize status register accordingly.

Does the 256-byte special sector require separate addressing or commands?

Yes - it uses dedicated opcodes (0x77 for read, 0x76 for write) and 16-bit address space (0x0000–0x00FF), independent of main array addressing. Access requires prior Write Enable (0x06) and is subject to same write protection rules. Content survives reflow because it resides in hardened metal-insulator-metal (MIM) capacitor structure distinct from main F-RAM array.

What is the maximum sustained write throughput achievable in continuous mode?

At 50 MHz SPI clock with 8-bit opcode + 3-byte address + 1-byte data per transaction, theoretical max is ~10.6 MB/s for single-byte writes. In practice, using Fast Read/Write commands with dummy cycles and page-aligned bursts, sustained throughput reaches 4.8 MB/s - limited by host controller SPI DMA bandwidth and CS deassertion timing, not device internal latency.

Can the Device ID and serial number be overwritten by the user?

No - Device ID (16-bit manufacturer + product code) is factory-programmed and read-only. Serial number (8 bytes) resides in writable registers and can be programmed once or multiple times via instruction 0x1B (Write Serial Number), but requires Write Enable and is subject to software write protection bits (SRWD, BP0/BP1) like main memory.