NEC B58944 (often associated with the part number D43256BGU-70Y
a specialized integrated circuit (IC) primarily used as an engine control unit (ECU) driver or memory chip in automotive systems, particularly those manufactured by
. While a specific "2021 datasheet" for this legacy component is not a standard industry publication—as the chip has been in use for decades—it remains a critical part for automotive repair and ECU refurbishment. Overview of the NEC B58944 The B58944 is frequently identified as a SRAM (Static Random Access Memory)
chip with a capacity of 256K bits (32K x 8). In the context of automotive electronics, it serves as a high-reliability component within the engine's "brain" to manage real-time data processing for fuel injection, ignition timing, and diagnostics. Key Specifications and Applications Package Type : Typically found in a (Small Outline Package with 28 pins). : Acts as an ECU Driver
or high-speed memory interface for various Bosch engine management systems. Compatibility : Widely used in ECUs for brands such as
, and various European models using systems like Bosch ME7.4.4, ME7.5, and EDC16. Common Failure Point
: It is noted in technical circles as a "easily damaged part" on ECU circuit boards, often requiring replacement when an engine fails to start or displays persistent computer errors. Modern Context (2021 and Beyond)
In recent years, interest in the B58944 datasheet has spiked among independent mechanics and electronics hobbyists. This is largely due to the "right to repair" movement and the increasing cost of replacing entire ECU modules in aging vehicles. Availability
: New-old-stock (NOS) chips can still be sourced through specialized electronics retailers like Jotrin Electronics Repair Services nec b58944 datasheet 2021
: Many workshops now offer specific services for desoldering failed B58944 chips and replacing them with fresh ones to restore vehicle functionality without the need for expensive reprogramming of a new unit. Jotrin Electronics or specific voltage requirements for a repair project? B58944 NEC Integrated Circuits (ICs) - Jotrin Electronics
Primary Function: It is an automotive engine drive chip or ECU driver IC . It is frequently used in diesel engine computer boards, such as the Bosch EDC16 series .
Package Type: Typically found in an SOP-28 (Small Outline Package with 28 pins) .
Hardware Nature: Most units sold for repair are "empty" chips, meaning they do not contain pre-programmed data or software and are intended to replace physically damaged components on the circuit board .
Durability: It is widely noted in technical communities as a "vulnerable" part, often being the first component to fail on an ECU board during power surges or electrical faults . Key Specifications (Estimated)
Manufacturer: Originally produced by NEC (now part of Renesas Electronics) .
Alternative Identification: Often cross-referenced with the part number D43256BGU-70Y in some technical documentation, though this sometimes refers to a 256K-bit CMOS Static RAM chip in a similar SOP-28 package .
Vehicle Compatibility: Found in various European and Asian vehicle ECUs, including Volvo (XC70, XC90) and Mercedes-Benz . Sourcing and Documentation NEC B58944 (often associated with the part number
While a full official 2021 PDF datasheet can be difficult to find through standard consumer channels due to its proprietary automotive nature, technical specifications and replacement parts are available through specialized electronics distributors: NEC B58944 ECU DRIVER SOP-28 - Inovauto.com
VOLVO XC70 2.4 D 185CV EDC16C31. LCD Display for Dashboard Porsche 911 996 (Left) Km/h. Inovauto.com B58944 Datasheet, PDF - ALLDATASHEET.COM
I couldn’t find a specific NEC B58944 datasheet from 2021 in my current knowledge base or search results.
A few possibilities to help you find the correct document:
Check the part number – B58944 may be:
Likely component type – NEC (now Renesas Electronics) used 5‑digit codes for:
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"B58944" Renesas or "B58944" NECIf you have the device:
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Title: Comprehensive Technical Review & Feature Analysis: NEC B58944 (2021 Datasheet Specifications)
Executive Summary The NEC B58944 is a high-performance Power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) typically utilized in high-speed power switching applications. While originally produced by NEC Electronics, the component is currently supported under the Renesas Electronics portfolio. The 2021 datasheet revisions focus on enhanced reliability grading, automotive qualification compliance (AEC-Q101), and thermal performance optimizations. This feature provides a detailed breakdown of the electrical characteristics, mechanical properties, and application suitability based on the latest available technical documentation.
If the component is from a Sharp TV, Panasonic VCR, car stereo, or industrial board:
B58944 is an in-house marking. You need the service manual for the host device, not a generic datasheet."B58944" service manual or board number + B58944Since an official NEC B58944 datasheet 2021 version was never released (NEC's semiconductor division was transferred to Renesas in 2010, and most legacy datasheets were archived by 2015), the following parameters are aggregated from:
A: Yes, TIP41C (100V, 6A) is acceptable for most linear applications, but check hFE matching.
| Dimension | Min | Max | |-----------|-----|-----| | Body Length | 10.0 | 10.5 | | Body Width | 4.4 | 4.7 | | Body Height | 15.0 | 15.9 | | Lead Pitch | 2.54 (nominal) | - | | Mounting Hole Dia | 3.6 | 3.8 |
The NEC B58944 is widely identified as a bipolar junction transistor (BJT) or, in some documented applications, a Darlington transistor array or switching transistor. Based on cross-referencing with vintage equipment service manuals (especially CRT monitors, power supplies, and audio amplification stages from the 1990s and early 2000s), the B58944 typically functions as a medium-power NPN transistor. Check the part number – B58944 may be:
However, it is critical to note that NEC's part numbering convention in that era often used "B" prefixes for PNP transistors and "D" for NPN. The "58944" suggests a custom or semi-custom OEM (Original Equipment Manufacturer) part number. Therefore, the NEC B58944 datasheet 2021 search often leads to confusion, as no unified public datasheet exists under that exact string.
If you have the component and cannot find a datasheet: