Some OEM orders used specialized pin configurations (e.g., reverse pinout for automated assembly). Always test.
When searching for the official “NEC B58944 datasheet 2021”, you might be surprised to find that a conventional data document from 2021 is not available. This is because the —also widely recognized as D43256BGU-70Y or μPD43256BGU —is a legacy automotive-grade memory IC that was manufactured before the 2020s and is no longer in active production by NEC. Nevertheless, professional engineers, automotive ECU repair specialists, and component resellers have gathered a substantial body of practical technical information about the chip. This long‑form article compiles all the key specifications, equivalents, sourcing tips, and repair guidance you need to understand and work with the NEC B58944 in 2021–2026, even without a dedicated 2021‑dated datasheet.
Viewed from the flat face with leads downward: nec b58944 datasheet 2021
chip in automotive electronic control units (ECUs), particularly those manufactured by . It is technically equivalent to the μPD43256BGU-70L part from NEC Electronics. Technical Specifications
| Parameter | Symbol | Value | Unit | | :--- | :--- | :--- | :--- | | | $V_DSS$ | 60 | V | | Gate-Source Voltage | $V_GSS$ | $\pm 20$ | V | | Drain Current (DC) | $I_D$ | 50 - 80 (variant dependent) | A | | Drain Current (Pulse) | $I_DP$ | Up to 200 | A | | Channel Temperature | $T_ch$ | 150 | $^\circ C$ | | Storage Temperature | $T_stg$ | -55 to 150 | $^\circ C$ | Some OEM orders used specialized pin configurations (e
The IC integrates specialized regulation properties designed to minimize power dissipation. This design prevents data corruption inside the memory registers during low-voltage cranking states (engine ignition drops). 2. Embedded Protection Circuits
The NEC B58944 functions as high-speed memory, enabling real-time data processing for engine driving chips in vehicles. Detailed technical parameters include: 256 Kib Parallel Static RAM (SRAM). Package Type: SOP-28 (Small Outline Package with 28 pins). This is because the —also widely recognized as
This chip is a critical component in the repair and maintenance of Electronic Control Units (ECUs) for several major automotive brands. Common ECU models that utilize the B58944 include:
NEC B58944 Datasheet: An In-Depth Guide to the 2021 Automotive ECU Controller (SOP-28)
The is a high‑speed 32K x 8‑bit (256 Kbit) CMOS static RAM (SRAM) . Its primary function is to store firmware, configuration data, or sensor‑specific coding (e.g., fuel injector calibrations) within engine control units (ECUs) and other electronic modules [10†L9-L11][19†L4-L6][21†L2-L4].