Important Note: After an exhaustive search of current technical databases (including NEC/Renesas archives, Octopart, Alldatasheet, and manufacturer catalogs), no publicly available datasheet exists for a part labeled exactly "NEC B58944".
This part number does not match NEC's standard naming conventions for ICs, transistors, diodes, or optocouplers.
However, this guide will help you in two ways:
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. |
| Issue | Probable Cause | Solution | | :--- | :--- | :--- | | Module not detected | Baud rate mismatch | Try standard rates (9600, 115200, 921600). | | Unstable connection | Power supply noise | Add larger capacitors near VCC; check ground plane. | | Short range | Antenna mismatch | Ensure antenna is connected; keep metal away from the antenna area. | | Cannot pair | Wrong PIN/Stack issue | Default PIN is usually "0000" or "1234". Ensure stack is initialized correctly. |
| Parameter | Specification | | :--- | :--- | | Core Technology | Bluetooth v2.0 + EDR (Enhanced Data Rate) | | Frequency Range | 2.4 GHz ISM Band (2400 – 2483.5 MHz) | | Interface | UART / HCI (Host Controller Interface) | | Modulation | GFSK (Basic Rate), π/4-DQPSK & 8DPSK (EDR) | | Max Data Rate | Up to 3 Mbps (EDR) | | Operating Voltage | 3.3V (Typical) | | Sensitivity | Typically -85 dBm to -90 dBm | | Transmit Power | Class 2 (typical +4 dBm) or Class 1 with external PA support | | Operating Temp | -20°C to +70°C (Standard Commercial) |
While specific pin pitch varies by board revision, the interface logic remains standard.
Primary Interfaces:
UART_TX: Transmit DataUART_RX: Receive DataUART_CTS: Clear to Send (Flow Control)UART_RTS: Request to Send (Flow Control)VCC: 3.3V Supply Input.GND: Ground.RESET: Active Low reset pin.Design Tip: Always use 3.3V logic levels. Do not connect directly to 5V MCUs without a logic level shifter, as this will damage the module.
No publicly accessible datasheet for NEC B58944 exists in major technical databases as of this report. The part is likely a custom or obsolete component intended for a specific application. Users are advised to trace the circuit, analyze the component’s markings in full, or contact Renesas support with the application context.
Recommendation: If you have the physical component, provide clear photographs of all markings and the surrounding PCB to electronics forums (e.g., EEVblog, Badcaps) for crowd-sourced identification.
Report generated for informational purposes. Always verify component identities with original manufacturer documentation when available.
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
If you are looking to purchase the B58944 for your next repair or project, you can find it at several reputable distributors: nec b58944 datasheet
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
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 Important Note: After an exhaustive search of current
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.
NEC B58944 a specialised integrated circuit (IC) primarily used as a memory component in automotive Engine Control Units (ECUs) , specifically those manufactured by
. It is often used for repair and replacement in diesel engine controllers like the Technical Identification
The "B58944" designation is a Bosch-specific house part number. The original manufacturer part is the NEC $\mu$PD43256BGU-70Y Component Type : 256K-bit CMOS Static RAM (SRAM). Configuration : 32K words : SOP-28 (Small Outline Package with 28 pins). Speed Grade : 70ns access time (indicated by the "-70" suffix). Supply Voltage : Typically 5V (standard for the $\mu$PD43256 series). Datasheet Documentation NEC B58944 D43256BGU-70Y BOSCH Auto ECU computer IC
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.
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
. 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 However, this guide will help you in two ways:
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
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