Given the difficulty finding it online, try these methods:
Most NEC semiconductor datasheets follow a standard layout. Here's what to look for:
NEC part numbers generally follow structured formats. B58944 does not match common NEC logic families (e.g., µPD for microcontrollers, 2SC/2SA for transistors, or Dxxxx for diodes). It resembles:
No matching results appear in:
The purpose of this report is to identify and describe the technical documentation (datasheet) for the NEC part number B58944, presumed to be an electronic component manufactured by NEC Corporation (now part of Renesas Electronics). The report also explains how to locate the datasheet or find a replacement.
NEC (now Renesas Electronics) typically marks small components with short, non-datasheet codes. "B58944" is likely one of these:
| Likely Scenario | What It Means | What To Look For | | :--- | :--- | :--- | | 1. Lot/Batch Number | "B58944" is a manufacturing date or lot code, not the part number. | Look for a separate 2-4 character alphanumeric code (e.g., "C123", "7D", "A4") – that is the real part number. | | 2. Transistor or Diode | NEC used "B" prefix for some RF transistors or diodes. | Search for NEC 2SB* (PNP transistor) or NEC 1SB* (diode). Example: 2SB589? But "44" doesn't fit. | | 3. Optocoupler | NEC made popular optocouplers (e.g., PS2501). | Check if the device has 4 or 6 pins. Part number would be PS**. | | 4. Custom/OEM Marking | Made for a specific company (e.g., Sony, Pioneer, car radio). | Find the board's schematic or service manual – not a public datasheet. |
Based on NEC’s component distribution, the B58944 likely served in:
To integrate the B58944 into a custom PCB, follow this minimal design checklist:
Troubleshooting and Repairing Auto ECUs: The NEC B58944 IC If you're in the world of automotive electronics repair, you've likely encountered the NEC B58944 . Often found in BOSCH automotive engine ECU
(Engine Control Unit) boards, this specialized integrated circuit (IC) is a critical component for engine management systems.
Because these chips are frequently targeted for repairs when an ECU fails, finding the right technical data is essential for a successful fix. Technical Specifications
The NEC B58944 is an integrated circuit typically housed in a (Small Outline Package with 28 pins). Jotrin Electronics Manufacturer: NEC Corporation (now part of Renesas Electronics). Package Type: Common Part Variants: Often labeled as NEC B58944 D43256BGU-70Y Compliance: Generally available as Lead-free/RoHS compliant. Jotrin Electronics Primary Applications This IC is most commonly used as an automotive engine drive chip nec b58944 datasheet
. It is a "workhorse" component within BOSCH ECU architectures. Technicians often look for this specific datasheet when troubleshooting: Engine Computer Failures:
Stalling, non-starting, or intermittent sensor errors can sometimes be traced back to a damaged B58944 chip. ECU Board Repair:
Instead of replacing an entire expensive ECU, many specialized shops replace this specific IC to restore functionality. Important Repair Note
If you are purchasing a replacement chip, be aware that many listings for the NEC B58944 describe it as an empty chip
. This means it may not contain the specific program or data required for your vehicle's specific engine mapping. Depending on the exact sub-function of the chip in your ECU (such as if it acts as a memory or programmable driver), you may need to program it or "clone" the data from the original chip if it is still readable. Where to Find the Datasheet
Finding the original manufacturer datasheet can be tricky for automotive-grade ICs as they are often proprietary. However, technical parameters and PDF summaries can often be found on specialized component platforms: Jotrin Electronics provides technical parameters and package details. ALLDATASHEET
is a standard go-to for PDF lookups, though automotive chips may sometimes only show basic pinout configurations. B58944 Datasheet, PDF - Alldatasheet. ALLDATASHEET.COM B58944 NEC Integrated Circuits (ICs) - Jotrin Electronics
The NEC B58944 is a specialized integrated circuit (IC) primarily used as an SRAM memory chip or driver within automotive Engine Control Units (ECUs), particularly those manufactured by Bosch. It is widely recognized in automotive repair circles as a common point of failure in vehicle computers for brands like Honda, Mercedes-Benz, and Volvo. Key Specifications & Equivalents Part Number: B58944
Full Identity: Often marked or cross-referenced as μPD43256BGU-70L or D43256BGU-70Y. Type: 256 Kbit (32K x 8) Static RAM (SRAM). Package: SOP-28 (Small Outline Package with 28 pins).
Speed: Typically rated at 70ns (indicated by the "-70" suffix). Manufacturer: NEC Electronics (now Renesas). Automotive Applications
The B58944 is a "vulnerable" component, meaning it is frequently the culprit when an ECU fails. It is found in several Bosch ECU families:
ME7 Series: Including ME7.4.4, ME7.5, ME7.9.6, and ME7.9.20. Given the difficulty finding it online, try these
EDC Series: Common in EDC7 and EDC16 units for heavy vehicles like Iveco.
Vehicle Compatibility: Used in Bosch-equipped computers for Honda, Mercedes-Benz, Volvo (XC70/XC90), and Iveco. Repair & Sourcing Tips
💡 Warning: If you are buying this for an ECU repair, these chips are often sold "empty" (without pre-programmed data) if they are being used as generic RAM, but always verify if your specific ECU application requires a programmed version.
Availability: You can find replacements on AliExpress and eBay for relatively low costs.
Datasheet Access: While a standalone "B58944" datasheet is rare because it's an OEM part number, you should search for the μPD43256B datasheet from NEC/Renesas to get full electrical timing and pinout details.
Specialist Vendors: Sites like Jotrin Electronics and ECUFix specialize in these automotive-grade ICs. Микросхема NEC B58944 D43256BGU-70Y
The NEC B58944 is an integrated circuit primarily used as a static random-access memory (SRAM) chip in automotive Engine Control Units (ECUs). It is commonly found in Bosch-manufactured ECUs for vehicles like Honda, Iveco, and various European models. Technical Specifications
According to industry databases and technical listings, the B58944 is equivalent to the μPD43256BGU-70L. Type: CMOS Static RAM (SRAM). Capacity: 256 Kilobits (32K x 8 bits). Package: SOP-28 (Small Outline Package with 28 pins).
Speed: Typically 70ns access time (indicated by the "-70" in the equivalent part number).
Compliance: Lead-free and RoHS compliant versions are available. Common Applications
This component is a critical driver or memory chip in several automotive computer systems, specifically: Bosch ECU Models: ME7.4.4, ME7.5, ME7.9.6, EDC7, and EDC16.
Vehicle Brands: Frequently used in Honda, Volvo (e.g., XC70, XC90), and Iveco engine management systems. Repair and Replacement No matching results appear in: The purpose of
The B58944 is often cited as a "damaged-prone" part in automotive circuit boards. When replacing it, technicians should note:
Empty Chip: Replacement chips purchased from retailers like Jotrin Electronics or ECUFix are typically "empty" and do not contain pre-programmed data, though as SRAM, they primarily serve as temporary data storage during operation.
Datasheet Access: Detailed technical parameters and pinouts can be found on platforms such as Elparts or AllDatasheet under its commercial equivalent, μPD43256BGU. B58944 - datasheet, pdf, info, parameters, stock - Elparts
The NEC B58944 is an automotive-grade integrated circuit primarily used in Bosch Electronic Control Units (ECUs) for engine management. In the automotive industry, it is widely recognized as a cross-reference or "mask" for the NEC D43256BGU-70Y, which is a high-speed CMOS static RAM chip. Core Function & Applications
The B58944 serves as a critical memory component within the ECU, handling real-time data storage and retrieval necessary for engine operations such as fuel injection, ignition timing, and air management.
Primary Use: Found in Bosch EDC15 and EDC16 diesel engine control boards, as well as various gasoline units.
Role: It acts as the "working memory" (SRAM) for the ECU’s microprocessor, storing temporary operational maps and sensor data during vehicle operation.
Common Repairs: This chip is frequently identified as a "vulnerable" or "easily damaged" part. Technicians often replace it to fix corrupted engine computer boards or "bricked" ECUs. Technical Specifications
Based on its identical counterpart, the D43256BGU-70Y, the B58944 features the following technical characteristics: Feature Specification Memory Type CMOS Static RAM (SRAM) Capacity 256K-bit (32,768 words x 8 bits) Access Time 70 ns (indicated by the "-70" suffix) Package Type 28-pin Plastic SOP (Small Outline Package) Voltage Range 2.7 V to 5.5 V (B version) Data Retention Low VCC data retention down to 2.0 V Key Features for Automotive Use
Battery Backup Support: Designed to retain data at very low voltages, allowing it to preserve critical adaptive data even when the vehicle's main power fluctuates.
Extended Temperature Operation: Built to withstand the harsh thermal environments typical of an engine bay.
High-Speed Processing: The 70 ns access time ensures the ECU can make micro-second adjustments to engine parameters based on sensor input. Микросхема NEC B58944 D43256BGU-70Y
Микросхема NEC B58944 D43256BGU-70Y памяти используется для замены в блоке управления Bosch. ecufix.ru NEC B58944 D43256BGU-70Y BOSCH Auto ECU computer IC
Note: After an extensive search of publicly available technical databases (including NEC Electronics/Renesas archives, distributor datasheet repositories, and general web indexes), no official or third-party datasheet for a component labeled exactly “B58944” could be located. This report therefore provides:
