CAT25256VI-GT3 - 256Kb SPI EEPROM, 20MHz, 8-SOIC | onsemi
MPN: CAT25256VI-GT3 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.62 | $0.62 |
| 10 | $0.55 | $5.50 |
| 100 | $0.44 | $44.00 |
| 500 | $0.38 | $190.00 |
| 1,000 | $0.32 | $320.00 |
CAT25256VI-GT3 Overview
A Serial EEPROM, also known as an E2PROM or Serial Electrically Erasable Programmable Read-Only Memory, is a non-volatile memory device that communicates over a serial bus such as SPI, I2C, or Microwire. The CAT25256 belongs to the SPI-interface EEPROM category, within the broader hierarchy of EEPROM -> non-volatile memory (NVM) -> memory IC -> semiconductor. Serial EEPROMs are typically used to store small amounts of configuration, calibration, or user data that must persist across power cycles, occupying far less board area than parallel EEPROMs or flash devices. The CAT25256VI-GT3 is offered in the industry-standard 8-SOIC footprint, making it a drop-in-friendly choice for both new designs and legacy system upgrades.
Key features include a 256 Kbit (32 Kbyte) memory density organized as 32,768 bytes, hardware write protection via the WP pin, and a HOLD pin that allows the host controller to pause a serial transaction without deselecting the device. The CAT25256VI-GT3 supports single supply voltages from 1.8 V to 5.5 V, with an extended operating temperature range of -40°C to +125°C suitable for industrial and automotive-grade environments.
The CAT25256VI-GT3 employs CMOS technology for low-power operation, and its page-write capability allows up to 64 bytes to be written in a single internal write cycle, dramatically reducing total programming time when compared to byte-at-a-time EEPROMs. The device uses a self-timed internal write mechanism with automatic erase-before-write, and the WP pin can be used to lock the upper memory quadrant or the entire memory array. The CAT25256VI-GT3 complies with SPI modes 0 and 3 (CPOL/CPHA = 0,0 or 1,1), making it compatible with virtually any microcontroller.
Typical applications include storage of user preferences in consumer appliances, configuration data in industrial controllers, calibration coefficients in sensor signal conditioning boards, and parameter storage in white goods, networking equipment, automotive modules, and any low-power embedded system. The wide 1.8 V to 5.5 V supply range also makes it ideal for battery-powered portable devices.
When designing with the CAT25256VI-GT3, ensure that the WP pin logic level is defined (tie to VCC if write protection is not used) and that the HOLD pin is tied to VCC if the host will not use it. Connect a 100 nF decoupling capacitor close to the supply pin to suppress supply-induced noise. Software routines should respect the maximum 5 ms page-write cycle time before initiating the next access. This page synthesizes distributor pricing, onsemi datasheet excerpts, drop-in alternatives, and engineering design notes that go beyond the manufacturer's part-number listing.
Drop-in alternatives for CAT25256VI-GT3 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
CAT25256VI-G
✅ Drop-In📋 Reference alternative (not in catalog)
CAT25256YI-GT3
✅ Drop-In📋 Reference alternative (not in catalog)
CAT25256HU4I-GT3
✅ Drop-In📋 Reference alternative (not in catalog)
25LC256-I/SN
✅ Drop-In📋 Reference alternative (not in catalog)
AT25256B-SSHL-T
✅ Drop-In📋 Reference alternative (not in catalog)
M95256-DFMN6TP
✅ Drop-In📋 Reference alternative (not in catalog)
CAT25256VI-GT3 Maximum Ratings & Electrical Characteristics
| Memory Type | EEPROM (Electrically Erasable Programmable Read-Only Memory), Non-Volatile |
| Memory Density | 256 Kbit (32 Kbyte) |
| Memory Organization | 32K x 8 (32768 bytes) |
| Interface / Bus | SPI (Mode 0 and Mode 3) and 3-Wire Serial |
| Maximum Clock Frequency | 20 MHz |
| Page Size | 64 bytes |
| Write Cycle Time | 5 ms (max, per page) |
| Endurance | 1,000,000 erase/write cycles per page (typical) |
| Data Retention | 100 years (typical) |
| Supply Voltage (VCC) | 1.8 V to 5.5 V |
| Active Read Current | 5 mA (max at 20 MHz, 5.5 V) |
| Standby Current | 1 uA (typical) |
| Operating Temperature | -40°C to +125°C (Industrial) |
| Package | 8-SOIC (0.154 inch / 3.90 mm body width) |
| Mounting Type | Surface Mount |
| Pin Count | 8 |
| Special Features | Hardware WP (Write Protect), HOLD pin, 64-byte page write buffer |
| RoHS Compliance | Compliant |
| MSL Level | 1 (per JEDEC J-STD-020) |
CAT25256VI-GT3 Pin Configuration
| Pin 1 | CS — Chip Select input, active low. Drives SPI frame boundaries; tie to VCC when unused. |
| Pin 2 | SO — Serial Data Out. Tri-state CMOS output, driven on the falling edge of SCK. |
| Pin 3 | WP — Write Protect, active high. Locks upper half of the memory array when driven high; tie to GND to disable. |
| Pin 4 | GND — Ground reference for the device. |
| Pin 5 | SI — Serial Data In. Latches data on the rising edge of SCK (Mode 0) or falling edge (Mode 3). |
| Pin 6 | SCK — Serial Clock input, up to 20 MHz. |
| Pin 7 | HOLD — Hold input, active low. Pauses an SPI transaction without deselecting; tie to VCC if not used. |
| Pin 8 | VCC — Power supply, 1.8 V to 5.5 V. Decouple with 100 nF to GND close to the pin. |
Typical Applications
CAT25256VI-GT3 is suitable for 6 applications: Industrial Sensor Calibration Storage, Consumer Appliance User Settings Retention, Automotive Audio Head-Unit Configuration, Industrial PLC Module Parameter Storage, Medical Device Patient Data Logging, Networking Switch Port Configuration.
Industrial Sensor Calibration Storage
The CAT25256VI-GT3's 256 Kbit density and 1.8 V to 5.5 V supply range make it ideal for storing factory calibration coefficients in industrial sensor signal conditioning boards. The 1 million write cycle endurance per page accommodates periodic in-field recalibration, while the 100-year data retention ensures coefficients remain accurate across long maintenance cycles. Placed on the sensor I2C/SPI bus of an MCU like STM32G071, the CAT25256VI-GT3 holds calibration tables, serial numbers, and date codes. The 8-SOIC footprint handles industrial temperature -40C to +125C specified in the onsemi datasheet without thermal derating.
Recommended
Consumer Appliance User Settings Retention
White-goods appliances such as washing machines, ovens, dishwashers, and HVAC units persistently store user preferences using the CAT25256VI-GT3 across power loss. The 32 Kbyte capacity easily accommodates cycle counts, error logs, language settings, and Wi-Fi credentials. According to onsemi, the device operates across 2.5V, 3.3V, and 5V rails commonly used in appliance control boards. The 1 million erase/write cycles per page handles lifetime usage in service menus and diagnostic counters. Its 8-SOIC footprint and single-byte write capability simplify firmware compared to flash-based alternatives.
Recommended
Automotive Audio Head-Unit Configuration
The CAT25256VI-GT3 with -40C to +125C industrial temperature range fits underhood-adjacent automotive subsystems such as audio head units, instrument clusters, and HVAC controls. It stores equalizer settings, radio presets, volume defaults, and Bluetooth pairing data that must persist across battery disconnect. Per onsemi the wide VCC range supports 3.3V and 5V automotive rails. Designers can substitute the onsemi same-family parts for AEC-Q100-grade variants in safety-critical subsystems. The 8-SOIC package withstands automotive reflow profiles up to 260C peak per JEDEC J-STD-020.
Recommended
Industrial PLC Module Parameter Storage
Programmable Logic Controller (PLC) analog and digital I/O modules store configuration parameters - including channel ranges, scaling factors, and HART device descriptors - in the CAT25256VI-GT3. The byte-addressable 256 Kbit density is sufficient for module-specific calibration constants and supports millions of reprogramming cycles during commissioning. According to onsemi the CMOS design draws only 1 uA standby, well below PLC bus budgets. The 8-SOIC footprint remains compatible with legacy 24XX I2C slot layouts when SPI mode is configured, easing retrofitting.
Recommended
Medical Device Patient Data Logging
Portable medical devices such as blood pressure monitors, glucose meters, and pulse oximeters use the CAT25256VI-GT3 to store dose logs, measurement history, and operator settings across battery cycles. Per onsemi the 100-year data retention ensures clinical logs remain intact over multi-year device lifespans. The wide 1.8 V to 5.5 V supply operates from two alkaline or a single Li-ion cell via an LDO. The 8-SOIC package supports MSL 1 moisture classification, simplifying manufacturing flow with less pre-bake time than higher-density parts.
Recommended
Networking Switch Port Configuration
Small-port industrial Ethernet switches and unmanaged network appliances use the CAT25256VI-GT3 to store VLAN tables, MAC filtering rules, and port configuration that must survive firmware reflash. The byte-level write capability and 1 million cycle endurance make it ideal for parameters that may be updated frequently during provisioning, while the 20 MHz SPI clock enables fast bulk configuration loads during system reset. Per the onsemi datasheet the HOLD pin allows the network processor to pause a transaction mid-frame, useful when interrupts preempt configuration reads.
Recommended
Recommended Products Summary
Engineering reference data for CAT25256VI-GT3 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | CAT25256VI-G | CAT25256YI-GT3 | 25LC256-I/SN | AT25256B-SSHL-T | M95256-DFMN6TP |
|---|---|---|---|---|---|---|
| Brand | onsemi | onsemi (same brand) | onsemi (same brand) | Microchip Technology | Microchip Technology | STMicroelectronics |
| Package | 8-SOIC | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same |
| Memory Density | 256 Kbit (32K x 8) | 256 Kbit (32K x 8) | 256 Kbit (32K x 8) | 256 Kbit (32K x 8) | 256 Kbit (32K x 8) | 256 Kbit (32K x 8) |
| Max Clock Frequency | 20 MHz | 20 MHz | 10 MHz | 10 MHz | 20 MHz | 20 MHz |
| Interface | SPI / 3-Wire | SPI / 3-Wire | SPI / 3-Wire | SPI | SPI | SPI |
| Page Size | 64 bytes | 64 bytes | 64 bytes | 64 bytes | 64 bytes | 64 bytes |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 2.5 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Operating Temperature | -40C to +125C | -40C to +85C | -40C to +125C | -40C to +85C | -40C to +125C | -40C to +85C |
| Standby Current | 1 uA typical | 1 uA typical | 1 uA typical | 1 uA typical | 1 uA typical | 1 uA typical |
Key Differentiators
- 20 MHz max clock with single 1.8 V to 5.5 V supply (vs 25LC256-I/SN)
- Industrial -40C to +125C temperature grade (vs AT25256B-SSHL-T)
- Same onsemi 8-SOIC family across full datasheet (vs CAT25256XI-T2 (8-TSSOP))
Design Notes
Place a 100 nF X7R decoupling capacitor within 5 mm of the VCC pin (pin 8) and connect the ground side directly to the GND pin (pin 4) via a wide, short trace. Keep the SCK trace matched-length and well-spaced from switching converter nodes to avoid coupling noise into the EEPROM. Route SI/SO away from the crystal or clock oscillator lines. If the WP and HOLD pins are unused, tie WP to GND and HOLD to VCC as close to the IC as possible to prevent floating-pin glitches during noisy power-up transients.
The SPI bus from the host MCU must support the CAT25256VI-GT3's maximum clock of 20 MHz with rise/fall times below 10 ns. Place a small 22 to 47 ohm series resistor near the host SCK driver if reflections are observed on long traces. Per the onsemi datasheet the SO pin is tri-stated when CS is high; ensure the host enables its internal pull-up on MISO only if the application requires a defined idle level. Avoid 3-wire mode unless you understand that SI and SO share a pin - most modern MCUs default to full 4-wire SPI which avoids contention.
Do not exceed 5 ms between successive write operations - poll the status register's WIP bit or wait the maximum page-write time, then check WEL before the next instruction. Cross-page writes wrap to the start of the page; if a write spans a page boundary, on-CAT25256VI-GT3 the lower address bits roll over and corrupt adjacent page data, so split writes at 64-byte boundaries. Per onsemi industrial specs, derate endurance linearly if operating continuously above +85C, so keep the part away from heat sources in sealed enclosures. Always confirm CS goes high before issuing a new command, otherwise the device remains selected and the next SCK edge will be misinterpreted as data.
Compliance Information
RoHS and lead-free per onsemi product page. Industrial-grade -40C to +125C; not AEC-Q100 qualified (consult onsemi automotive channels for higher-grade variants).
