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Renesas X28HC256SIZ-90
- Part No.:
- X28HC256SIZ-90
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
X28HC256SIZ-90.pdf
- Description:
- IC EEPROM 256KBIT PAR 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,241
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Product details
Overview
X28HC256SIZ-90 from Intersil is a 256 kbit (32k × 8), 5V-only, byte-alterable EEPROM with 90 ns access time, -40°C to +85°C industrial temperature range, and RoHS-compliant 28-lead SOIC package. It delivers high-reliability nonvolatile storage for firmware configuration, calibration data, and system parameters in embedded controllers and industrial PLCs.
For engineers reviewing the X28HC256SIZ-90 datasheet, X28HC256SIZ-90 pinout, X28HC256SIZ-90 application, or X28HC256SIZ-90 equivalent, key selection criteria include its 100,000 write-cycle endurance, 100-year data retention, page-write capability (128-byte burst), and dual early-write-detection methods (DATA polling on I/O7 and Toggle bit on I/O6).
Technical Context
The X28HC256SIZ-90 implements a CMOS-based Direct Write™ floating-gate cell architecture with textured poly technology, enabling true 5V-only operation without external high-voltage programming circuits. Its control logic supports both CE- and WE-controlled write cycles, with address latching on the last falling edge of CE or WE.
It features two independent hardware write-inhibit mechanisms-default VCC sense (inhibits writes below ~3.5 V) and signal-level inhibition (OE low / WE high / CE high)-plus JEDEC-standard software data protection activated via a three-byte unlock sequence. Page write timing requires consecutive WE strobes within 100 µs to avoid premature internal programming initiation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory capacity | 256 kbit (32,768 × 8 bits); supports full memory rewrite in <0.8 s using 128-byte page writes |
| Access time | 90 ns; enables direct interface with 10 MHz bus systems without wait states |
| Endurance | 100,000 write/erase cycles per byte; validated for long-term field deployment in infrequently updated parameter storage |
| Data retention | 100 years at +25°C; ensures firmware or calibration data integrity across product lifecycle without refresh |
| Supply voltage | 5 V ±10%; operates reliably across industrial rail tolerances without external regulation |
| Operating temperature | -40°C to +85°C; qualified for use in harsh environments including factory automation and outdoor telemetry |
| Standby current | 500 µA (CMOS inputs); minimizes power draw during system sleep modes |
Pinout & Package
Package: 28-lead SOIC (300-mil, RoHS-compliant, MDP0027 footprint). Pin count and physical layout match JEDEC MS-013-AE standard.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address inputs | 15-bit address bus selecting one of 32,768 bytes; A7–A14 define page boundaries for 128-byte page writes |
| I/O0–I/O7 | Data input/output | Bidirectional 8-bit data bus; I/O7 provides DATA polling status, I/O6 provides Toggle bit status |
| CE | Chip Enable | Active-low primary device select; must be LOW to enable read/write; HIGH places outputs in high-Z and reduces ICC to 500 µA |
| OE | Output Enable | Active-low output gate; controls data bus drivers during reads; used with CE to eliminate bus contention in multi-device systems |
| WE | Write Enable | Active-low write control; latches address/data with CE; initiates byte or page write when both CE and WE are LOW and OE is HIGH |
| VCC | Power supply | +5 V supply pin; decoupling requires 0.1 µF ceramic capacitor per device plus 4.7 µF bulk cap per 8 devices |
| VSS | Ground | Reference ground for all signals and power; must be low-impedance connection to minimize noise coupling into EEPROM array |
Key Features
| Feature | Design Value |
|---|---|
| Direct Write™ cell technology | Enables true 5V-only operation with no external HV circuitry, eliminating BOM cost and board space for charge pumps |
| 128-byte page write | Reduces full-memory update time from >30 s (byte-by-byte) to <0.8 s, critical for field firmware patching |
| DATA polling (I/O7) | Allows host CPU to poll completion status without interrupts or timers-reduces software overhead and latency |
| Toggle bit detection (I/O6) | Eliminates need to store last written address/data for polling; simplifies multi-device array management |
| JEDEC software data protection | Nonvolatile lock activated by 3-byte sequence; prevents accidental writes during power transitions without external hardware |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data |
|---|---|
|
Use Scenario: Storing user-configurable I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in factory environments. IC Role / Device Role / Timing Role: Nonvolatile parameter register bank accessed via parallel bus during boot and runtime reconfiguration. Use Value: 100,000-cycle endurance supports decades of field updates; -40°C to +85°C rating ensures reliability in uncontrolled cabinet temperatures. |
Use Scenario: Retaining sensor calibration coefficients, patient safety limits, and regulatory audit logs in portable diagnostic equipment. IC Role / Device Role / Timing Role: Secure, tamper-resistant configuration memory with software lock to prevent unauthorized parameter changes. Use Value: 100-year data retention meets FDA long-term recordkeeping requirements; RoHS compliance satisfies global medical device directives. |
| Telecom Base Station Firmware | Automotive Body Control Module |
|
Use Scenario: Holding boot loader configuration, RF channel tables, and fault history in remote radio units operating in outdoor enclosures. IC Role / Device Role / Timing Role: High-speed (90 ns) parallel EEPROM interfaced directly to microcontroller's external memory bus. Use Value: Page write capability enables rapid field upgrades over backhaul links; VCC-sense hardware protection prevents corruption during brownout events. |
Use Scenario: Storing seat position memory, window auto-up/down profiles, and lighting presets in vehicle body control units. IC Role / Device Role / Timing Role: Low-power (500 µA standby) nonvolatile storage accessed intermittently during ignition cycles. Use Value: Industrial temp range accommodates under-hood thermal cycling; software protection prevents inadvertent reset of user preferences. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256-90PU | Same 256 kbit × 8, 90 ns, 5V, PDIP-28; endurance 100,000 cycles but only commercial temp (0°C to +70°C) | Lacks industrial temperature rating; unsuitable for extended ambient exposure or automotive under-hood use | Select only for cost-sensitive commercial-grade designs where thermal margin is guaranteed |
| M95256-DW DW | 256 kbit SPI EEPROM, 5V, 8-pin SOIC; slower effective throughput due to serial interface and command overhead | Requires SPI controller and software driver; eliminates parallel bus routing but increases firmware complexity | Prefer when board space is constrained and microcontroller lacks parallel bus, accepting trade-off in write speed and interrupt latency |
Compared with AT28C256-90PU and M95256-DW DW, the X28HC256SIZ-90 uniquely combines industrial temperature support, parallel bus speed, and robust hardware/software write protection-making it optimal for mission-critical embedded systems requiring deterministic, high-integrity parameter storage.
Availability
X28HC256SIZ-90 is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, and telecom infrastructure requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.
Supply support for X28HC256SIZ-90 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
Intersil Corporation is a leader in precision analog and power management ICs, serving industrial, infrastructure, and high-end consumer markets with high-reliability semiconductor solutions.
The X28HC256 series was designed specifically for robust, 5V-only nonvolatile storage in embedded systems demanding long data retention, high endurance, and immunity to power-supply transients during write operations.
FAQ
What is the maximum write cycle time for a single byte on the X28HC256SIZ-90?
The X28HC256SIZ-90 specifies a maximum write cycle time (tWC) of 5 ms for a single byte under typical conditions. This is the worst-case duration the device requires to complete internal programming after the write command is issued. Early termination can be detected using DATA polling on I/O7 or Toggle bit on I/O6, allowing the host to resume operations before tWC expires.
Does the X28HC256SIZ-90 require external high-voltage circuitry for programming?
No, the X28HC256SIZ-90 uses Intersil's proprietary textured poly floating-gate technology to enable full 5V-only operation. It requires no external high-voltage generators, VP-P control circuits, or complex programming algorithms-only standard TTL/CMOS-level CE, OE, WE, and address/data signals.
How does software data protection work on the X28HC256SIZ-90?
Software data protection on the X28HC256SIZ-90 is activated by writing three specific values (0xAA, 0x55, 0xA0) to addresses 0x5555, 0x2AAA, and 0x5555 respectively. Once enabled, the X28HC256SIZ-90 remains write-protected until this sequence is repeated or the six-step reset algorithm is executed-ensuring immunity to spurious writes during power transitions.
Can the X28HC256SIZ-90 be used in a system with a 3.3V microcontroller interface?
No-the X28HC256SIZ-90 is strictly a 5V device with TTL-compatible input thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V) and 5V output swing (VOH ≥ 2.4 V, VOL ≤ 0.4 V). Interfacing directly to a 3.3V microcontroller risks violating input voltage limits and may cause unreliable operation; level-shifting circuitry is required.
What is the pin compatibility between X28HC256SIZ-90 and other X28HC256 variants?
The X28HC256SIZ-90 shares identical pinout and signal definitions with all SOIC-packaged X28HC256 variants (e.g., X28HC256SI-90, X28HC256SIZ-12), including A0–A14, I/O0–I/O7, CE, OE, WE, VCC, and VSS. However, PLCC and PDIP variants use different packages and footprints-only SOIC variants are physically interchangeable on PCBs.
X28HC256SIZ-90 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- 90 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOIC
X28HC256SIZ-90 FAQ
1.How can I place an order for X28HC256SIZ-90 through Aetrix?
Please submit a Request for Quotation (RFQ) for X28HC256SIZ-90 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 X28HC256SIZ-90 reliable?
The price and inventory of X28HC256SIZ-90 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for X28HC256SIZ-90 is usually 5 days.
3.What payment methods are accepted for X28HC256SIZ-90?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for X28HC256SIZ-90 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for X28HC256SIZ-90?
X28HC256SIZ-90 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your X28HC256SIZ-90 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 X28HC256SIZ-90?
For technical support, including X28HC256SIZ-90 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your X28HC256SIZ-90 requirements.
6.How does Aetrix verify that X28HC256SIZ-90 is sourced from the original manufacturer or authorized distributors?
All X28HC256SIZ-90 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 X28HC256SIZ-90 meets industry standards.
7.What is the process for return or replacement of X28HC256SIZ-90?
All X28HC256SIZ-90 units undergo pre-shipment inspection (PSI). If there is an issue with X28HC256SIZ-90, 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 X28HC256SIZ-90 part is unused and in its original packaging.
Return procedure for X28HC256SIZ-90:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
X28HC256SIZ-90 Tags
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