Nec B58944 Datasheet |work| 〈500+ FAST〉

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 nec b58944 datasheet

Step 2: How to Find the Correct NEC Datasheet (General Method)

Once you have the true part number (e.g., NEC 2SC945, NEC PS2561, NEC uPD78F0537), use this method:

  1. Go to a reliable datasheet aggregator:

    • www.alldatasheet.com
    • www.datasheetcatalog.com
    • www.octopart.com

  2. Search with the exact NEC prefix:

    • 2SCxxxx (NPN transistor)
    • 2SBxxxx (PNP transistor)
    • PSxxxx (Optocoupler)
    • uPDxxxx (Microcontroller)
    • µPCxxxx (IC – note the micro symbol)

  3. If you can't find it: NEC parts are often discontinued. Go to Renesas Electronics (they bought NEC) and search their legacy products section.

Typical Applications

Based on NEC’s component distribution, the B58944 likely served in: NEC B58944 is an integrated circuit, specifically identified

  1. CRT Monitor Horizontal Deflection Circuit – Many NEC monitors (e.g., Multisync series) used 7-pin SIP ICs for H-out or V-out pre-drivers. The B58944 could be a replacement for defective vertical output ICs like LA7830 or TDA1170.

  2. Automotive Voltage Regulator – Japanese car radios and ECUs from the late 1980s (Toyota, Nissan, Honda) often featured NEC hybrids for 8V or 5V regulation from the car battery.

  3. VCR Servo Control – NEC’s VCRs (Video Cassette Recorders) used custom hybrid ICs for capstan and drum motor drivers. B58944 might appear on main control boards alongside NEC D78C10 microcontrollers.

  4. Power Supply Modules – Industrial equipment with NEC-labeled power bricks sometimes contain these hybrids for ±12V or ±15V generation.

Typical applications

  • Motor or relay drivers in consumer electronics
  • Line drivers and audio pre-drivers
  • Power stage in small appliances or industrial controls
  • Hobbyist projects requiring moderate current switching

NEC B58944 — Brief Technical & Contextual Report

Overview

  • Part: B58944 (NEC / Bosch marking seen in automotive listings)
  • Package: SOP-28 (TSOP/SO-28 variants reported)
  • Likely function: 256K (32K x8) parallel SRAM / ECU driver memory IC equivalent to μPD43256 series (references show "eq. μPD43256BGU-70L" / D43256BGU-70) used in automotive ECU modules.

Key electrical / packaging facts (compiled from distributor listings and datasheet aggregators)

  • Memory density: 256 Kib (32K x 8) — commonly used as static RAM in legacy embedded/ECU systems.
  • Speed grade references: “-70” marking in variants (70 ns).
  • Supply & package: typical µPD43256-style parts use single 5 V VCC and come in SOP-28 packages.
  • Common marking/aliases: D43256BGU-70, μPD43256, B58944 (NEC/Bosch cross-reference in auto parts catalogs).
  • RoHS/lead-free variants reported by distributors.

Typical application & context

  • Frequently sold as “ECU driver” or “ECU memory” replacement for Bosch engine control units (ME7.x, EDC7/EDC16 families listed by aftermarket sellers).
  • Appears commonly in automotive ECU repairs as a socketed or surface-mounted SRAM used to store runtime data, maps, or as a buffer in older ECUs. Some listings indicate “empty chip — no program/data” (sold as replacement hardware).

Pinout / functional notes (assumed from μPD43256 family)

  • 28-pin SOP pinout: A0–A14 address lines (15 address lines = 32K locations), I/O0–I/O7 data lines, OE, CE (chip enable), WE, VCC, VSS.
  • Control signals: standard SRAM control (active-low outputs for OE, CE; WE for write enable).
  • Timing: typical access times (e.g., 70 ns) define maximum bus frequency for read/write cycles.

Reliability, sourcing, and repair considerations

  • Component age: these SRAM parts are legacy; many listings show aftermarket/used inventory. Beware counterfeit/used parts when buying for critical repairs.
  • Automotive usage: ECUs often require chips with automotive-grade screening; aftermarket replacements may be generic NEC/Renesas derivatives.
  • Data persistence: SRAM is volatile—any stored ECU calibration/programming typically resides in external EEPROM/flash; if this SRAM stores volatile runtime data it will be blank on replacement unless backed up/restored by specialized ECU tools.

Where to find datasheet / more details

  • Distributor/product pages (Jotrin, Elparts, AllDataSheet) and automotive parts sellers list the part and cross-references (search for μPD43256 / D43256BGU-70 / μPD43256 datasheet for exact electrical/timing specs).
  • For exact electrical characteristics and timing diagrams use the μPD43256 (or D43256) datasheet from NEC/Renesas — these share the same density and pinout.

Practical summary for repair/modification

  • If replacing B58944 in an ECU: confirm package pinout, speed grade, and that the replacement is the correct density (256 Kib) and acceptable speed; verify whether the ECU expects pre-programmed contents. Use verified suppliers and, for programming/restore, ECU-specific cloning or reprogramming tools.

If you want, I can:

  • Extract the full μPD43256 (D43256) datasheet electrical tables and timing diagram and present the exact pin functions and voltage/timing numbers.