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Renesas X28HC256PIZ-12
- Part No.:
- X28HC256PIZ-12
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-DIP (0.600", 15.24mm)
- Datasheet:
-
X28HC256PIZ-12.pdf
- Description:
- IC EEPROM 256KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,158
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Product details
Overview
X28HC256PIZ-12 from Intersil is a 256 kbit (32k × 8), 5V-only, byte-alterable CMOS EEPROM with 120 ns access time, fabricated using textured poly floating gate technology. It delivers 100,000 write cycles per byte and 100-year data retention, supporting page writes of up to 128 bytes for sub-second full-memory rewrites - used in industrial control firmware storage and embedded configuration memory where reliable nonvolatile write capability is required.
For engineers reviewing the X28HC256PIZ-12 datasheet, X28HC256PIZ-12 pinout, X28HC256PIZ-12 application, or X28HC256PIZ-12 equivalent, key selection considerations include its -40°C to +85°C industrial temperature range, PDIP-28 RoHS-compliant package, JEDEC software data protection, and dual early-write-detection methods (DATA polling on I/O7 and Toggle bit on I/O6).
Technical Context
The X28HC256PIZ-12 implements a two-line control architecture (CE and OE) to eliminate bus contention in multi-device memory arrays. Its internal timing logic latches address on the last falling edge of CE or WE and data on the first rising edge of either signal, enabling both CE-controlled and WE-controlled write cycles.
It integrates Direct Write™ cell technology with hardware VCC-sense write inhibition below ~3.5 V and supports software data protection via a three-byte unlock sequence to AA/5555h, 55/2AAAh, and A0/5555h - a nonvolatile setting that persists until reset by a six-step algorithm.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory capacity | 256 kbit (32,768 × 8 bits) - provides sufficient space for boot code, calibration tables, or device configuration in resource-constrained embedded systems. |
| Access time | 120 ns - enables direct interfacing with 8-bit microcontrollers operating at ≤8 MHz without wait states. |
| Write endurance | 100,000 cycles per byte - supports frequent field-updatable parameters in industrial sensors or programmable logic controllers. |
| Data retention | 100 years at +25°C - ensures long-term integrity of stored settings without battery backup or refresh circuitry. |
| Supply voltage | 5 V ±10% - compatible with legacy 5V TTL/CMOS logic families and eliminates need for level-shifting in retrofitted designs. |
| Operating temperature | -40°C to +85°C - qualified for use in industrial automation, automotive under-hood modules, and outdoor metering equipment. |
| Page write size | 128 bytes - reduces total programming time to <0.8 s for full memory rewrite, improving firmware update efficiency. |
| Standby current | 500 µA (CMOS inputs) - minimizes power draw in always-on systems such as smart grid endpoints or remote telemetry units. |
Pinout & Package
Package: 28-pin Plastic Dual In-line Package (PDIP), RoHS-compliant, body width 0.600 inch (15.24 mm), standard through-hole mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address inputs | 15-bit address bus selects one of 32,768 bytes; A7–A14 define page boundaries for 128-byte page writes. |
| I/O0–I/O7 | Data input/output bidirectional bus | 8-bit parallel interface; I/O7 provides DATA polling status, I/O6 provides Toggle bit status during write cycles. |
| CE | Chip Enable | Active-low primary device select; when HIGH, places device in low-power standby mode (500 µA) and disables outputs. |
| OE | Output Enable | Active-low read control; used with CE to implement two-line read protocol and prevent bus contention in shared-data-bus systems. |
| WE | Write Enable | Active-low write control; latches data on rising edge; supports both CE- and WE-initiated write cycles per JEDEC timing. |
| VCC | Power supply | +5 V supply; internally regulated for EEPROM programming; includes VCC-sense circuitry to inhibit writes below ~3.5 V. |
| VSS | Ground | Reference return path for all digital and programming currents; requires local 0.1 µF ceramic decoupling per device. |
Key Features
| Feature | Design Value |
|---|---|
| Self-timed byte/page write | No external timing components or erase-before-write required; internal state machine completes 3–5 ms write cycle automatically. |
| Early write completion detection | Hardware-supported DATA polling (I/O7) and Toggle bit (I/O6) allow host CPU to poll instead of using fixed delays - cuts average write latency by >50%. |
| JEDEC-standard software data protection | Three-byte unlock sequence (AA/5555h → 55/2AAAh → A0/5555h) enables nonvolatile write lockout - prevents corruption during brown-out or reset events. |
| Direct Write™ floating-gate cell | Textured poly technology ensures 100,000-cycle endurance and 100-year retention without wear leveling or controller overhead. |
| Two-line control architecture | Independent CE and OE inputs enable selective device activation in multi-chip memory banks - eliminates bus contention and simplifies arbitration logic. |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Memory |
|---|---|
|
Use Scenario: Storing user-defined I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in factory environments. IC Role / Device Role / Timing Role: Nonvolatile configuration register bank accessed via 8-bit parallel bus during boot and runtime parameter updates. Use Value: 100,000 write cycles support daily recalibration logs; -40°C to +85°C rating ensures reliability in unconditioned control cabinets. |
Use Scenario: Retaining sensor calibration coefficients, patient history flags, and safety-critical operational limits in portable diagnostic instruments. IC Role / Device Role / Timing Role: Secure, tamper-resistant configuration store accessed only during service mode or factory initialization. Use Value: Software data protection prevents accidental overwrites during power transitions; 100-year retention meets FDA long-term device lifecycle requirements. |
| Automotive Body Control Module (BCM) | Smart Energy Meter Firmware Backup |
|
Use Scenario: Holding door lock logic states, mirror position presets, and lighting profiles in vehicle BCMs exposed to under-hood thermal cycling. IC Role / Device Role / Timing Role: Secondary nonvolatile memory backing up SRAM-based runtime variables during ignition-off periods. Use Value: 120 ns access time allows real-time read access during CAN message processing; PDIP package withstands wave-solder reflow per Intersil spec. |
Use Scenario: Preserving firmware checksums, tariff schedules, and tamper-event logs in utility-grade electricity meters operating 20+ years in outdoor enclosures. IC Role / Device Role / Timing Role: Fail-safe firmware metadata repository updated infrequently but requiring absolute write integrity. Use Value: Hardware VCC-sense and software lock ensure no spurious writes during grid voltage sags; RoHS-compliant PDIP supports lead-free assembly. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256-15PU | 150 ns access time; same 28-pin PDIP, 5V operation, 32k×8 organization; 100,000 cycles, 100-year retention. | Lacks Toggle bit polling; uses only DATA polling; no software data protection - relies on hardware write protect pin (WP). | Select when simpler status monitoring suffices and external WP control is preferred over software lock. |
| MX28LV256APCI-12 | 120 ns access time; 28-pin PDIP; 5V core, but supports 3.3V I/O; 100,000 cycles, 100-year retention; includes hardware WP pin. | Requires separate 3.3V I/O supply; no software data protection; different pinout (WP replaces NC on pin 1). | Choose for mixed-voltage systems needing 3.3V-compatible I/O while retaining 5V EEPROM functionality. |
Compared with AT28C256-15PU and MX28LV256APCI-12, the X28HC256PIZ-12 offers unique dual-status polling (I/O6/I/O7) and nonvolatile software lock - critical for systems where firmware integrity must survive uncontrolled power loss without external pins or voltage rails.
Availability
X28HC256PIZ-12 is available at Aetrix Electronics and suitable for industrial control, medical diagnostics, automotive body electronics, and smart metering applications requiring stable component supply across extended product lifecycles.
Supply support for X28HC256PIZ-12 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 semiconductor company specializing in precision analog and power management ICs, with deep expertise in nonvolatile memory design for industrial and infrastructure markets.
The X28HC256PIZ-12 belongs to Intersil's second-generation high-reliability EEPROM product line, engineered specifically for robustness in harsh environments where long-term data integrity and deterministic write behavior are mandatory.
FAQ
What is the maximum write cycle time for X28HC256PIZ-12?
The X28HC256PIZ-12 specifies a maximum write cycle time (tWC) of 5 ms for byte writes. During page writes, the internal programming cycle begins after the final byte load, and the entire 128-byte page typically completes within 0.8 seconds. The device supports DATA polling (I/O7) and Toggle bit (I/O6) to detect completion earlier than the worst-case 5 ms bound - enabling tighter software timing loops without fixed delays. This behavior is confirmed in the AC Electrical Specifications and Figure 6 of the FN8108 datasheet.
Does X28HC256PIZ-12 require external high-voltage programming?
No, the X28HC256PIZ-12 operates with a single 5 V supply and requires no external high-voltage programming circuitry. Its proprietary textured poly floating gate technology enables full byte and page writes using only VCC = 5 V ±10%. All timing, erase, and programming functions are self-contained and internally managed - eliminating the need for charge pumps, VP-P generators, or complex external timing control. This is explicitly stated in the datasheet introduction and Features section.
How does software data protection work on X28HC256PIZ-12?
Software data protection on the X28HC256PIZ-12 is enabled by writing three specific values to three addresses: 0x5555 (data 0xAA), 0x2AAA (data 0x55), then 0x5555 (data 0xA0). Once set, further writes are blocked until this sequence is repeated. The protection is nonvolatile and persists through power cycles. To disable it, a six-step reset sequence is required. This mechanism is documented in Figures 12–15 and the Software Data Protection section of the FN8108 datasheet.
What is the meaning of "PIZ" in X28HC256PIZ-12?
In the part number X28HC256PIZ-12, "P" denotes 28-pin PDIP package, "I" indicates industrial temperature range (-40°C to +85°C), "Z" signifies RoHS-compliant packaging (lead-free terminations and molding compound), and "-12" specifies 120 ns access time. This coding is defined in the Ordering Information table on page 2 of the FN8108 datasheet and aligns with Intersil's standard nomenclature for EEPROM variants.
Can X28HC256PIZ-12 be used in place of X28HC256PI-12?
Yes, X28HC256PIZ-12 is functionally and pin-compatible with X28HC256PI-12. The "Z" suffix denotes RoHS compliance, while the base part X28HC256PI-12 refers to the same industrial-grade PDIP device with identical electrical specifications, timing, and pinout. Both share the same marking "X28HC256PI-12 HYZ" per the Ordering Information table, confirming equivalence except for environmental compliance certification.
X28HC256PIZ-12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-DIP (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- -
- 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:
- 120 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-PDIP
X28HC256PIZ-12 FAQ
1.How can I place an order for X28HC256PIZ-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for X28HC256PIZ-12 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 X28HC256PIZ-12 reliable?
The price and inventory of X28HC256PIZ-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for X28HC256PIZ-12 is usually 5 days.
3.What payment methods are accepted for X28HC256PIZ-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for X28HC256PIZ-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for X28HC256PIZ-12?
X28HC256PIZ-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your X28HC256PIZ-12 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 X28HC256PIZ-12?
For technical support, including X28HC256PIZ-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your X28HC256PIZ-12 requirements.
6.How does Aetrix verify that X28HC256PIZ-12 is sourced from the original manufacturer or authorized distributors?
All X28HC256PIZ-12 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 X28HC256PIZ-12 meets industry standards.
7.What is the process for return or replacement of X28HC256PIZ-12?
All X28HC256PIZ-12 units undergo pre-shipment inspection (PSI). If there is an issue with X28HC256PIZ-12, 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 X28HC256PIZ-12 part is unused and in its original packaging.
Return procedure for X28HC256PIZ-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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