Nec B58944 Datasheet Here

Ensure you are using the SOP-28 variant, as 256K SRAMs also exist in DIP (Dual Inline Package) formats which will not fit the PCB footprints of modern ECUs.

If you are currently troubleshooting a specific module,I can provide the pin checkout procedures or help you track down matching donor ECUs! Share public link

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:

The µPB58944 (often styled NEC B58944) is a legacy integrated circuit from NEC (now Renesas) family — a silicon BJT or analog/drivers family part (datasheets and exact part designation vary across sources). Below I assume you mean the common vintage NEC part designated B58944 (power/driver IC). If you meant a different exact part number, say so and I'll adapt.

If you are purchasing a replacement chip, be aware that many listings for the NEC B58944 describe it as an empty chip nec b58944 datasheet

Because it is an OEM-specific part primarily manufactured for proprietary automotive modules, finding a standardized public datasheet can be notoriously difficult for independent technicians and engineers. This guide synthesizes the known technical specifications, package parameters, structural applications, and troubleshooting protocols associated with the NEC B58944. Technical Overview and Identification

The NEC B58944's main role is in a car's ECU, where it likely serves as a data buffer or scratchpad. Its core function is to manage and act as a Double Channel Solid-State Relay (IC Relay) —these are electronically controlled switches that turn power on and off to various automotive systems on the "high side" (the +12V side) of the load. The table below lists known ECUs.

Including ME7.4.4, ME7.5, and ME7.9.6 (common in Honda and Volkswagen/Audi groups).

Like all MOSFETs, this component is sensitive to static electricity. Handle with proper grounding. Ensure you are using the SOP-28 variant, as

The B58944 is often cited as a "damaged-prone" part in automotive circuit boards. When replacing it, technicians should note:

The B58944 is typically produced as a leaded, lacquer-coated disk or an encapsulated epoxy bead/probe, offering excellent long-term stability and high accuracy within its operating range. 2. NEC B58944 Key Specifications (Datasheet Summary)

Factory-new replacement parts sourced from electronics suppliers are completely blank chips containing no predefined code .

Efficient heat management is vital for the B58944 to prevent thermal runaway. Maximum 150°C to 175°C. Storage Temperature ( Tstgcap T sub s t g end-sub ): -55°C to +175°C. Thermal Resistance ( Blank State: The µPB58944 (often styled NEC B58944)

While specific pin pitch varies by board revision, the interface logic remains standard.

: Stores temporary handshaking values decrypted during vehicle startup sequences.

: Deployed primarily in commercial vehicles and heavy-duty diesel engines. Diagnosing B58944 Failures

If you can tell me the (e.g., TDK, EPCOS, NEC) or the full part number (often printed on the packet or component), I can help you find the precise data sheet or equivalent components . Arduino code for temperature conversion? A comparison of this part to another thermistor?