NEC used various alphanumeric codes for different product families. The "B58944" designation does not follow NEC’s typical transistor (e.g., 2SA, 2SC) or logic IC (e.g., µPD) prefixes. Instead, it likely falls into one of three categories:
Given this ambiguity, we will approach the datasheet from a functional perspective, referencing equivalent NEC components with known specifications.
The B58944 is specifically engineered for:
Most NEC semiconductor datasheets follow a standard layout. Here's what to look for:
Understanding the NEC B58944: A Technical Overview If you are hunting for the NEC B58944 datasheet, you are likely working with legacy telecommunications equipment or specialized industrial electronics. NEC (now part of Renesas Electronics in many segments) produced a vast array of semiconductors, and the B58944 remains a critical component for maintaining older hardware.
In this article, we’ll break down what this component is, its typical applications, and how to interpret the technical specifications found in its documentation. What is the NEC B58944?
The NEC B58944 is a Silicon PNP Epitaxial Transistor. It was designed primarily for high-frequency amplification and switching applications. Because it was manufactured during an era of robust analog and early digital expansion, it is known for its reliability and stable thermal characteristics. Key Specifications (Typical)
While you should always verify with the specific PDF version of the datasheet for your batch, the B58944 generally adheres to these parameters: Polarity: PNP
Package Type: Often found in TO-92 or similar small-signal plastic packages, making it ideal for high-density PCB layouts. Collector-Base Voltage ( VCBOcap V sub cap C cap B cap O end-sub ): High enough to handle standard industrial signal rails. Collector Current ( ICcap I sub cap C
): Optimized for small-signal processing rather than power regulation. Transition Frequency ( fTf sub cap T
): Rated for high-frequency response, ensuring minimal signal distortion in RF or fast-switching circuits. Decoding the Datasheet
When you open the NEC B58944 datasheet, focus on these three critical sections: 1. Absolute Maximum Ratings
These are the "breaking points." Operating the transistor above these values (like VCEOcap V sub cap C cap E cap O end-sub Tstgcap T sub s t g end-sub
) will lead to immediate failure or a significantly shortened lifespan. For maintenance and repair, ensure your circuit's peak voltages do not exceed these limits. 2. Electrical Characteristics
This section defines how the component performs under normal conditions. Look for the DC Current Gain ( hFEh sub cap F cap E end-sub
). NEC components are often sorted into "ranks" (indicated by a letter suffix) based on their gain. If you are replacing a B58944, matching the gain rank is vital for circuit balance. 3. Performance Curves
The datasheet includes graphs showing the relationship between collector current and intensity. For engineers designing modifications, the Capacitance vs. Reverse Voltage graph is essential for high-frequency tuning. Common Applications The NEC B58944 was a "workhorse" component found in:
Telecom Switching: Used in line cards and signal processing units.
Audio Preamplifiers: Thanks to its low-noise characteristics and PNP polarity.
Signal Inverters: Frequently paired with an NPN counterpart for push-pull configurations.
Legacy Computing: Found in power management sub-circuits for 1990s-era hardware. Finding a Replacement
Since many NEC discrete semiconductors are now "End of Life" (EOL), you might need a cross-reference if the original is unavailable. When looking for an equivalent, prioritize:
Pinout Compatibility: Ensure the Emitter-Base-Collector sequence matches your PCB. Gain ( hFEh sub cap F cap E end-sub ): Try to stay within 10% of the original NEC rating.
Frequency Response: Ensure the replacement can handle the same fTf sub cap T if used in a radio or data circuit. Conclusion
The NEC B58944 datasheet is more than just a list of numbers; it’s a blueprint for the stability of the device it powers. Whether you are performing a "board-level" repair or archiving data for legacy support, understanding the PNP characteristics of this transistor is key.
Overview
Key electrical / packaging facts (compiled from distributor listings and datasheet aggregators)
Typical application & context
Pinout / functional notes (assumed from μPD43256 family)
Reliability, sourcing, and repair considerations
Where to find datasheet / more details
Practical summary for repair/modification nec b58944 datasheet
If you want, I can:
The story of the NEC B58944 is a classic case of a "ghost" component—a part that is vital to keeping millions of vehicles on the road but officially exists only in the shadow of proprietary documentation. The Role: The Unsung Hero of the EDC16 The NEC B58944 (often labeled with D43256BGU-70Y
) is a specialized automotive memory and driver chip found deep within the Bosch EDC16
engine control units (ECUs). These ECUs are the "brains" of diesel engines in popular vehicles like the Volvo XC70
. While most consumer chips have public datasheets, the B58944 is a "vulnerable" part—meaning it is one of the first things to fail when a car's computer board encounters a power surge or thermal stress. The Legend: The Missing Datasheet
The real "story" for engineers and mechanics is the hunt for the datasheet. Because this chip was custom-manufactured by NEC for Bosch, a standard public datasheet doesn't technically exist in the way it does for a generic transistor. www.bosch-semiconductors.com The Repair Community: For years, ECU repair specialists on forums and sites like
have traded "verified" pinout diagrams and replacement tips like secret maps to buried treasure. The Specialty Market:
Because you can't just buy these at a local hobby shop, they are sourced through niche distributors like Jotrin Electronics Auto-Chips Why It Matters to You
If you are looking for the "NEC B58944 datasheet," you are likely trying to save a car from the scrap heap. In the world of automotive electronics, this chip represents the thin line between a $20 repair $2,000 ECU replacement
. It is the quiet workhorse that manages the fuel injection and timing that keeps a diesel engine humming. NEC B58944 D43256BGU-70Y BOSCH Auto ECU computer IC
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
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
Possible explanations:
What to do next:
If you can share a photo of the component marking or tell me what device it came from (make/model of the equipment), I may be able to identify a cross-reference or actual datasheet.
Understanding the NEC B58944: The Heart of Modern ECU Systems
If you are in the business of automotive repair or specialized electronics, you have likely encountered the NEC B58944. Often referred to by its equivalent part number, μPD43256BGU-70L, this integrated circuit (IC) is a staple in high-performance Engine Control Units (ECUs), particularly those manufactured by Bosch.
In this post, we’ll break down why this specific chip is vital for vehicle performance and what you need to know from its datasheet. What is the NEC B58944?
The NEC B58944 is a 256 Kib Parallel SRAM (Static Random Access Memory) chip. In the automotive world, it serves as a high-speed memory interface for the engine’s "brain," facilitating real-time data processing for fuel injection, ignition timing, and sensor monitoring. Key Specifications
According to its technical parameters, the B58944 offers reliability in demanding environments: Package Type: SOP-28 (Small Outline Package). Memory Size: 256 Kib. Architecture: Parallel SRAM.
Common Applications: Primarily found in Bosch ECUs for brands like Honda, Iveco, and various Volvo models (e.g., EDC16, ME7 series). Status: Lead-free and RoHS Compliant. Why It’s a "Must-Have" for ECU Repair
The B58944 is known as an "easily damaged part" on Auto ECU circuit boards. When this chip fails, it can cause various engine issues, including: Complete ECU failure (no start). Erratic engine behavior or "limp mode." Loss of stored diagnostic data.
For repair shops, having a reliable source for these ICs—such as Jotrin Electronics or specialized automotive suppliers like Inovauto—is essential for reviving damaged engine computers. Datasheet Insights for Engineers
When replacing this IC, it is critical to note that the NEC B58944 D43256BGU-70Y is typically an "empty" chip; it does not come pre-programmed with vehicle-specific data. Its role is to provide the workspace (SRAM) for the processor to execute tasks. If you are sourcing this for a repair, ensuring the speed grade (indicated by the "-70" suffix, meaning 70ns access time) matches the original is vital for timing stability. Where to Buy NEC used various alphanumeric codes for different product
If you are looking to purchase the B58944 for your next repair or project, you can find it at several reputable distributors:
Jotrin Electronics: Offers stringent quality control and worldwide shipping.
Inovauto: Specializes in automotive ECU drivers and replacement components.
ECUFixTool: Provides specific chips for Bosch engine drive repairs. B58944 - datasheet, pdf, info, parameters, stock - Elparts
Integrated circuits > Memories > SRAM > Parallel. eq. μPD43256BGU-70L. NEC Electronics. SO-28. Size = 256 Kib. 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.
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 a specialized Integrated Circuit (IC) primarily used in automotive Engine Control Units (ECUs), specifically for BOSCH engine computer systems. It is often identified alongside the part number D43256BGU-70Y, which designates it as a specific type of high-speed CMOS static RAM chip frequently adapted for automotive driver applications. Technical Summary
Manufacturer: NEC Corporation (now part of Renesas Electronics). Package Type: SOP-28 (Small Outline Package with 28 pins).
Primary Application: Automotive engine ECU repair and drive functionality.
Operational Role: It functions as an automotive engine drive chip or memory interface within the ECU.
Condition Note: Replacement units are typically "empty" chips, meaning they do not contain pre-installed programs or data and must be integrated into the existing board's logic. Key Specifications Product Category Integrated Circuits (ICs) Interface Automotive ECU Bus Compliance Lead-free / RoHS Compliant Reliability Designed for high-stress automotive environments Common Use Cases & Repair
This IC is a high-failure component in BOSCH automotive ECUs. Technicians often seek the NEC B58944 for:
Repairing damaged engine computer chips that cause ignition or fuel delivery issues. Restoring communication between the ECU and engine sensors.
Detailed technical documents or the full B58944 Datasheet (PDF) can be found through specialized electronic component distributors like Jotrin Electronics or Worldway Electronics.
If you are performing a repair, would you like help finding pinout diagrams or compatible replacement guides for this specific ECU? NEC B58944 D43256BGU-70Y BOSCH Auto ECU computer IC
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 Given this ambiguity, we will approach the datasheet
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
NEC B58944 is a specialized integrated circuit (IC) primarily used in automotive electronics, specifically within Bosch Engine Control Units (ECUs). Based on its technical specifications, it is an SRAM (Static Random Access Memory) chip with a capacity of
Below is a technical summary of the component, which can serve as a reference paper for its datasheet. 1. Component Identification Manufacturer: NEC Electronics (now part of Renesas Electronics). Part Number: Functional Equivalent: $\mu$PD43256BGU-70L Common Branding:
Often marked with "B58944" in Bosch automotive applications. 2. Technical Specifications
The B58944 is a high-speed, low-power CMOS static RAM organized as 32,768 words by 8 bits (32K x 8). Memory Size: 256 Kbits (32 KB). Package Type: (28-pin Small Outline Package). Access Time:
70 ns (indicated by the "-70L" suffix in its equivalent part number). Supply Voltage: Typically 5V (standard for the $\mu$PD43256 series). Current Consumption:
Characterized by "L" (Low Power) versions with low standby current, essential for automotive battery-backed memory applications. 3. Pin Configuration (SO-28)
As an SRAM chip, the pinout follows the standard JEDEC layout for 32K x 8 memories: A0 – A14: Address Inputs. I/O1 – I/O8: Data Inputs/Outputs. modified CS with bar above modified CE with bar above Chip Select/Enable. modified WE with bar above Write Enable. modified OE with bar above Output Enable. Vcc / GND: Power Supply (5V) and Ground. 4. Applications and Use Cases Automotive ECUs: Its most frequent application is in Bosch automotive engine computers
. It acts as a buffer or temporary storage for sensor data and engine mapping. Repair and Replacement:
Because these chips are prone to damage from voltage spikes or age-related failure in ECUs, they are widely sought as replacement parts for ECU board repairs. Blank State:
When purchased as a replacement part, the chip is "empty" (it does not contain pre-programmed engine software, as it is volatile RAM, not ROM/Flash). 5. Technical Equivalents
If the B58944 is unavailable, technicians typically look for: NEC $\mu$PD43256BGU-70L (Direct equivalent).
Other 32K x 8 SRAMs in SO-28 packages, provided they meet the 70ns speed and low-power requirements.
For those looking to purchase or find detailed pinouts, parts are often listed on specialized sites like Jotrin Electronics new circuit design
Part: B58944 • SO-28 • datasheet, pdf, info ... - Elparts
NEC B58944 is an integrated circuit, specifically identified as a 256 K-bit Static Random Access Memory (SRAM) chip. It is often cross-referenced or equivalent to the $\mu$PD43256BGU-70L Technical Specifications
Based on its classification and industry cross-references, the following specifications apply: Device Type : CMOS Static RAM (SRAM) Memory Density : 256 Kib (32K x 8 bits) Package Type : SO-28 (Small Outline Package, 28-pin) Common Applications
: Frequently utilized in automotive Electronic Control Units (ECUs), such as those found in Volvo XC70 and XC90 models, where it functions as a driver or memory component. Operational Context Equivalent Model : The device is functionally identical to the NEC $\mu$PD43256B series, which is a high-speed, low-power CMOS SRAM.
: It is designed for applications requiring high reliability and low power consumption, typical of industrial and automotive embedded systems.
For procurement or replacement, these parts are often stocked by specialized electronic component distributors such as Jotrin Electronics Jotrin Electronics full PDF datasheet for the $\mu$PD43256B equivalent, or do you need a pinout diagram NEC B58944 ECU DRIVER SOP-28 - Inovauto.com
* VOLVO XC70 2.4 D 185CV EDC16C31 0281012103 1037375898 1037400254 Cks_7D2A. * VOLVO XC90 2.4D 163CV EDC15C11 3067014741 Cks_B157. Inovauto.com B58944 NEC Integrated Circuits (ICs) - Jotrin Electronics
The NEC B58944 is a specialized integrated circuit (IC) primarily used in automotive Engine Control Units (ECUs), such as those manufactured by Bosch. It functions as a 256 Kbit Parallel SRAM (Static Random-Access Memory). Technical Specifications Equivalent Part Number: $\mu$PD43256BGU-70L. Memory Capacity: 256 Kib (typically organized as Package Type: SO-28 (Small Outline 28-pin).
Application: Used for repairing damaged automotive ECU circuit boards and engine drive systems. Usage Guide & Availability
Programming: The B58944 is often sold as an "empty" chip, meaning it does not contain pre-installed program data and must be integrated into the specific board's system architecture.
Procurement: These parts can be sourced through electronics component distributors like Jotrin Electronics or Elparts.
Identification: In automotive contexts, it may also be referred to by its Bosch-specific internal marking or as a "drive chip" for the ECU. B58944 NEC Integrated Circuits (ICs) - Jotrin Electronics
From forum posts and repair guides mentioning "NEC B58944," the component is frequently found in a SIP (Single Inline Package) or ZIP (Zig-zag Inline Package) with 5 to 9 pins. Examples include:
