Nec B58944 Datasheet __full__ Free May 2026

I understand you're looking for a free datasheet for the NEC B58944. However, I need to let you know that:

1. The part number "B58944" does not appear to be a standard NEC (now Renesas) semiconductor part number in their common line-up (like 2SC/B, µPD, etc.). It may be:

   • A custom/OEM part number (used by a specific device manufacturer, e.g., in a TV, monitor, or power supply).
   • A marking code (top marking on a small component), not the full part number.
   • A transistor, diode, or IC with a partial or misremembered number.

2. Free sources to try (but search by possible correct part):

   • DatasheetArchive (datasheetarchive.com)
   • Alldatasheet (alldatasheet.com)
   • DatasheetCatalog (datasheetcatalog.com)
   • Renesas Electronics (successor to NEC) – official site

3. What you can do to find it:

   • Check the full marking on the component (e.g., B58944 might be a lot code, date code, or partial).
   • Look at the circuit/device it came from (power supply, amplifier, driver) – that helps identify likely part type.
   • Search for "B58944 NEC" but also try removing "NEC" or adding "datasheet" in quotes.
   • If it's a transistor, check cross-references to 2SB** or 2SC** series.

4. Ethical note:

   • Free datasheet sites are generally tolerated for older/discontinued parts, but official sources are best.
   • I cannot directly provide or link to copyrighted datasheets, but I can help you identify the correct part number if you provide:
     • Photo of component markings
     • Device make/model it came from
     • Package type (TO-220, SOT-23, etc.)

Would you like help decoding the marking, finding a replacement, or identifying the actual part number instead?

The NEC B58944 is a specialized automotive integrated circuit, frequently used as a memory chip in Bosch Engine Control Units (ECUs). It is functionally equivalent to the μPD43256BGU-70L, a 256 Kbit CMOS static RAM.

Below is a draft post for a technical forum or social media group to help others find or understand this component.

📝 Post Draft: Troubleshooting Bosch ECUs with the NEC B58944

Title: Technical Brief: NEC B58944 (μPD43256BGU) in Automotive ECU Repair

If you’re working on automotive engine control modules, particularly those from Bosch, you’ve likely come across the NEC B58944. This chip is a common point of failure on many circuit boards and is essential for proper engine computer function. Key Technical Specs: Type: Parallel Static RAM (SRAM). Density: 256 Kib (32K x 8 bits). Package: SO-28 (Small Outline 28-pin). Equivalent Part: μPD43256BGU-70L (NEC Electronics).

Application: Commonly used as an automotive engine drive chip in ECU boards. Repair Notes:

Blank Chips: Replacement B58944 chips are typically sold "empty"—meaning they do not come with pre-loaded programs or data.

Fragility: This IC is known to be a "damaged-prone" part during ECU repairs; always ensure proper ESD precautions and heat management when soldering.

Datasheet Access:You can find full technical parameters and PDF documentation for the μPD43256BGU series (the commercial equivalent) on major databases like AllDatasheet or Elparts.

#ECURepair #AutomotiveElectronics #NEC #BoschECU #B58944 #ElectronicsEngineering NEC B58944 D43256BGU-70Y BOSCH Auto ECU computer IC

a specialized integrated circuit (IC) primarily used in BOSCH automotive engine control units (ECUs)

. It is frequently identified as an "empty" chip, meaning it requires specific programming and data to function within a vehicle's engine management system. Technical Details & Function Alternative Identification : It is often cross-referenced with the D43256BGU-70Y Primary Use

: Found on automotive ECU circuit boards as an engine drive chip. Common Issues

: It is known as an "easily damaged part" that technicians use to repair faulty automotive computers. Datasheet and Availability

While a dedicated "B58944" datasheet is rare because it is an automotive-grade proprietary part, technical information for the related

series is more widely available on professional components sites. Repair & Parts nec b58944 datasheet Free

: You can find listings for this specific chip at automotive electronics suppliers like Ecufixtool or general electronic component distributors such as Jotrin Electronics PDF Search : General datasheet repositories like ALLDATASHEET

NEC B58944 is not a standard discrete transistor but rather a specialized automotive integrated circuit (IC) or high-density memory chip primarily used in Bosch Engine Control Units (ECUs)

. Because it is a proprietary part manufactured for Bosch, a "public" datasheet is rarely released by NEC. 🛠️ Key Technical Identity Part Number: B58944 (also associated with the full marking D43256BGU-70Y Manufacturer: NEC (now Renesas Electronics). Primary Use: Bosch automotive ECU circuit boards as a memory or engine drive chip. Repair Context:

It is known as an "easily damaged part" in automotive computers; technicians often seek it for repairing damaged engine ECU boards. 📂 How to Find "Datasheet" Information

Since a single-file PDF datasheet for the B58944 is generally unavailable to the public, experts use these alternatives: Cross-Referencing: The marking D43256BGU-70Y indicates it is a member of the D43256 series , which is a 256K-bit CMOS Static RAM . You can find technical specs for the general D43256 family on ALLDATASHEET to understand its pinout and timing characteristics. Reputable Suppliers:

Parts are sometimes available via specialist electronics brokers like Jotrin Electronics Ecufixtool

, which provide basic application data for automotive repair. Schematics: Instead of a component datasheet, search for the Bosch ECU schematic

(e.g., Bosch Motronic) for your specific vehicle model. This will show the B58944's role and pin connections within the actual circuit. Jotrin Electronics ⚠️ Technical Warning The B58944 is typically sold as an "empty chip"

The NEC B58944 (often associated with part number D43256BGU-70Y) is a critical integrated circuit (IC) primarily used as an automotive engine ECU (Electronic Control Unit) computer chip. It is most frequently found in Bosch automotive engine ECUs and serves as an engine drive or memory component. Technical Overview Role: Engine drive chip / ECU memory replacement. Associated Part Number: D43256BGU-70Y.

Format: Typically provided as an "empty" chip, meaning it requires external programming or data flashing specific to the vehicle's engine map before it can function.

Common Applications: Repairing damaged automotive ECU circuit boards where the original drive chip has failed. Sourcing Datasheet Information

Finding a standalone "free" PDF datasheet for the internal NEC B58944 proprietary numbering can be difficult because it is an OEM-specific part for Bosch systems. However, users often look for the D43256 series datasheet, which covers the underlying memory architecture.

Reliable platforms for locating these technical documents include:

ALLDATASHEET: A general search for B58944 might return related diode or transistor specifications, so ensure you verify the D43256BGU variant for ECU-specific applications.

Jotrin Electronics: Lists the part as an integrated circuit and provides basic inventory and manufacturer details.

ECU Fix Tools: Provides practical context for the chip's use in automotive repair and ECU maintenance. Critical Considerations for Repair If you are using this chip for ECU repair:

Programming: As noted by ECUFIX, new B58944 chips are "empty" and will not work unless programmed with the correct data for your specific Bosch ECU model.

Damage Profile: This component is considered a "highly damaged" part on ECU boards, often failing due to electrical surges or heat stress within the engine bay. B58944 Datasheet, PDF - ALLDATASHEET.COM

The NEC B58944 is a specialized integrated circuit (IC) primarily utilized in automotive electronics, specifically within Bosch engine control units (ECUs). Often categorized as an "ECU Driver" or "Diesel Engine Computer Board Chip," it plays a critical role in the processing and management of automotive sensor data and actuator control. Technical Overview & Specifications

While standard consumer datasheets for this specific part are often proprietary to automotive manufacturers, technical summaries from industrial suppliers highlight several key characteristics:

Package Type: Typically available in a SOP-28 (Small Outline Package), making it suitable for high-density automotive circuit boards. I understand you're looking for a free datasheet

Manufacturer: Produced by NEC (now part of Renesas Electronics).

Primary Application: Used as an interface or driver chip in various Bosch ECU families, including ME7.x (found in many Honda and European vehicles) and EDC16 (common in diesel engines like those in Volvo and Iveco).

Operational Role: It is an "empty chip" by default, meaning it requires external programming or is part of a larger system that manages the vehicle's firmware. Why You Need the B58944 Datasheet

Engineers and automotive technicians seek the "NEC B58944 datasheet free" primarily for ECU repair. This chip is known to be a common point of failure on automotive module controller boards. Accessing the pinout and electrical parameters is essential for:

Fault Diagnosis: Verifying if voltage levels at specific pins match expected values during engine troubleshooting.

Replacement: Ensuring correct orientation and soldering during the replacement of a damaged IC.

Circuit Mapping: Understanding how the ECU communicates with sensors and injectors. Where to Find Documentation

Because this is an automotive-grade component, you won't always find it on standard retail sites. Specialized repositories are the best source for technical data:

Industrial Component Libraries: Sites like Jotrin Electronics and Alldatasheet often host partial specifications or technical parameters for legacy NEC parts.

ECU Repair Forums: Platforms like ECUFixTool provide practical application data and repair videos that often substitute for official datasheets in a workshop setting.

Manufacturer Archives: For deep technical inquiries, the Renesas Electronics Document Search (formerly NEC) may have archived data for its "B" series ICs. Common Vehicle Compatibility

The B58944 is frequently found in the following vehicle control modules: Volvo: XC70 (2.4 D) and XC90.

Iveco: Various diesel models utilizing the EDC16 engine computer. Honda: Specific ME7 series Bosch ECUs.

Warning: When replacing the B58944, ensure the suffix (e.g., D43256BGU-70Y) matches exactly, as different versions may have varied timing or voltage tolerances required for specific ECU firmware.

Post: How to Find the NEC B58944 Datasheet (Free)

The Short Answer: The B58944 is not a standard NEC semiconductor part number (like a microcontroller or transistor). It is almost certainly a custom OEM part number, likely a display (LCD) or a hybrid module from a specific device (e.g., a car stereo, cash register, or industrial equipment).

Because it's custom, NEC/Renesas will not have a public datasheet. You will need to search by application.

Step-by-Step Search Strategy (Free):

1. Check Alldatasheet.com (Start Here)

   • Go to www.alldatasheet.com
   • Search for B58944 (without NEC).
   • If nothing appears, search for NEC B58944 in quotes.

2. Check Datasheet Archive & Utsource

   • www.datasheetarchive.com
   • www.utsource.net (search the part number – they often have scans of obscure datasheets linked to product listings).

3. Identify the Host Device (Most Effective)

   • Look at the PCB the part came from. Search for other part numbers on the board (e.g., "NEC D78F..." microcontroller, or a model number like "NR-D58...").
   • Search Google: "B58944" "NEC" -datasheet -pdf (the minus signs filter out fake "datasheet" spam sites).
   • Search eBay or AliExpress for NEC B58944 – product photos sometimes show the component pinout or markings.

4. If It's an LCD (Likely)

   • Count the number of pins on the component.
   • Search for a generic replacement using: [pin count] pin character LCD module or NEC dot matrix LCD [pin count].
   • Many NEC custom LCDs are compatible with HD44780 or SED1278 controllers. Try those driver datasheets instead.

5. Last Resort: Reverse Engineer

   • If you can't find the datasheet, use a multimeter to map power (Vcc/GND), contrast (Vo), and data lines. Compare to standard LCD pinouts (e.g., 16x2 character LCD).

Important Warning: Avoid sketchy "free datasheet" sites that ask for a credit card or require you to download a .exe file. These are malware. Stick to the sites above.

The NEC B58944 is a specialized integrated circuit (IC) widely recognized within the automotive electronics industry. If you are searching for the NEC B58944 datasheet, it is essential to understand that this part is an OEM-specific (Original Equipment Manufacturer) component, often appearing in Bosch automotive Engine Control Units (ECUs).

This guide provides technical insights into its specifications, equivalents, and how to access relevant data for repair or design. Technical Overview of NEC B58944

The NEC B58944 is primarily identified as a SRAM (Static Random Access Memory) chip or an ECU driver, typically housed in an SOP-28 package. In automotive applications, it serves as a critical memory buffer or driver for managing temporary data during engine operation.

Standard Equivalent: The industry-standard equivalent for the NEC B58944 is the μPD43256BGU-70Y (or μPD43256 series). Memory Architecture: 256 Kbit (32K x 8 bits) Parallel SRAM. Package Type: SOP-28 (Small Outline Package with 28 pins).

Access Time: Typically 70ns (indicated by the "-70" suffix). Common Applications

You will most frequently encounter the B58944 in Bosch ECUs for various vehicle models, including: Honda: ME7.x series. Volvo: EDC16 series. Iveco: EDC7 and EDC16 controllers. Audi/VW: ME7.5 and ME7.5.10 units.

Because this IC is a "vulnerable" component (prone to failure due to thermal stress or voltage spikes), it is a common target for automotive ECU repair professionals. How to Download the NEC B58944 Datasheet for Free

Since "B58944" is a proprietary house number, searching for it directly on standard datasheet portals might return limited results. To find the full technical specifications for free, search for its commercial counterpart:

Search for μPD43256B: Use the Alldatasheet or DatasheetArchive to find the original NEC/Renesas μPD43256B datasheet.

Verify the Package: Ensure the datasheet covers the SOP-28 variant to match the B58944's physical footprint.

Check ECU Fix Sites: Specialist automotive repositories like ECUFix or Inovauto often host pinout diagrams and repair guides specifically for the B58944. Key Specifications to Look For

When reviewing the μPD43256B (B58944) datasheet, pay close attention to these parameters: Supply Voltage ( VCCcap V sub cap C cap C end-sub

): Usually 5V for automotive units, though low-voltage versions (3.3V) exist.

Operating Temperature: Automotive grades often require -40°C to +85°C or higher. Pin Configuration: Match the Chip Enable ( CEcap C cap E ), Output Enable ( OEcap O cap E ), and Write Enable ( WEcap W cap E ) pins to ensure compatibility during replacement.

Based on the part number NEC B58944, this component is a High-Voltage Monolithic IC (Hybrid IC) designed specifically for Electroluminescent (EL) Lamp Backlight Drivers. These are commonly used to illuminate LCDs in automotive dashboards, PDAs, and older mobile phones.

Here is the complete feature breakdown and datasheet summary for the NEC B58944.

C. "Spam/Freemium" Lockers

• Sites: Various sites with URLs like pdf-, datasheetfile`, etc.
• Reliability: 1/10.
• Review: These are the sites that explicitly target keywords like "free." They often promise a download but require you to:
  • Sign up for an account.
  • Pay a subscription fee (ironically, for a "free" datasheet).
  • Click through misleading "Download" buttons that are actually ads.
• Warning: Avoid these. They rarely have documents that distributors don't have for free without the hassle.

Conclusion: Your Path to the Free NEC B58944 Datasheet

The search for the "nec b58944 datasheet Free" is a journey through the golden age of Japanese semiconductors. While this specific part is obscure and likely a custom OEM component, the document does exist somewhere—likely in a dusty service manual or on a retired engineer’s hard drive.

Your action plan:

1. Start with Alldatasheet.com and DatasheetArchive.com.
2. If those fail, search the device name (TV, radio, car stereo) on ElektroTanya.
3. Join Badcaps or Reddit r/AskElectronics to request a scan.
4. Never pay for a datasheet. If it isn't free, it isn't legitimate.

By following this guide, you will either secure the PDF or gather enough electrical data to repair your device through reverse engineering. The NEC B58944 may be mysterious, but with perseverance, its secrets can be unlocked—without spending a dime. The part number "B58944" does not appear to

Have a copy of the NEC B58944 datasheet? Share the link in the comments below to help the next engineer!

Disclaimer: This article is for educational and repair purposes. NEC and Renesas are trademarks of their respective owners. Always follow ESD safety precautions when handling unknown ICs.