Nec B58944 Datasheet ((free)) ⏰
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
Other 32K x 8 SRAMs in SO-28 packages, provided they meet the 70ns speed and low-power requirements.
Understanding the NEC B58944: The Heart of Modern ECU Systems
The 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
. It acts as a buffer or temporary storage for sensor data and engine mapping. Repair and Replacement: nec b58944 datasheet
The SOP-28 configuration of the B58944 follows standardized physical form-factor dimensions to ensure tight integration into high-density multi-layer PCBs. Physical Footprint (SOP-28 Specifications)
Because it is an automotive-grade component cross-referenced under custom manufacturer part numbers, finding a unified datasheet can be challenging for technicians. This comprehensive guide synthesizes the technical specifications, architecture, pinout configurations, and troubleshooting steps for the NEC B58944 (D43256BGU-70Y). Architectural Overview and Core Features
These chips are generally "empty" or volatile. They do not store permanent firmware themselves but act as a workspace for the main processor. If you replace one, you generally do not need to "reprogram" the chip itself, though you must ensure the rest of the ECU's firmware is intact.
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 The "B58944" designation is a Bosch-specific house part
Connected to the load; the metal tab is also internally connected to the drain for cooling.
): Low junction-to-case resistance to allow for massive heat transfer to a heatsink. 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 commonly found in DC-DC converters, motor controllers, and power management systems where efficiency is critical. Advanced Trench Process Speed Grade : 70ns access time (indicated by
The 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).
If you are sourcing this part for hardware testing or bench repairs, components can be procured from independent international suppliers. You can review inventory quantities, package statuses, and quote requests through specialized platforms like Jotrin Electronics B58944 Database , ECUFixTool Automotive ICs , or general electronic tracking archives like Alldatasheet . Always verify that your replacement unit explicitly matches the SOP-28 package dimension to ensure it drops cleanly onto your specific Bosch ECU board version.
The B58944 is engineered for high-speed switching and low on-state resistance (
Report generated for informational purposes. Always verify component identities with original manufacturer documentation when available.