DP83905AVQB - 10BASE-T Ethernet Controller | Texas Instruments
MPN: DP83905AVQB ✗ End of LifeDP83905AVQB Overview
An Ethernet controller integrates the digital protocol, media-access, and physical-layer functions needed to connect a legacy personal computer or embedded ISA bus to a 10BASE-T twisted-pair network. The DP83905 supports the AT/LANTIC protocol family, IEEE 802.3 operation, and 10BASE-T signaling. Because the physical layer is integrated, a compliant design can use the controller with the appropriate line-driver, filter, isolation, and magnetics interface rather than implementing the complete PHY separately.
Verified device attributes include a 4.75 V to 5.25 V supply range, nominal 100 mA supply current, IEEE 802.3 network support, 10BASE-T PHY operation, ISA host interfacing, a commercial temperature grade of 0 °C to 70 °C, and a 160-BFQFP package. The device is identified as obsolete in the supplied manufacturer-related documentation, so it is most appropriate for maintenance of legacy AT-compatible networking equipment rather than new mass-production designs.
The DP83905AVQB belongs to the former National Semiconductor controller portfolio now served by Texas Instruments. Its large 160-pin gull-wing QFP construction is characteristic of late-1980s and early-1990s PC interface controllers, when integrating the AT bus logic, network controller, and 10BASE-T PHY into one device reduced component count and simplified legacy adapter-card design.
Typical uses include industrial legacy controllers, AT-compatible Ethernet adapters, embedded data-acquisition systems, and repair or obsolescence-management programs for installed networking equipment. The ISA interface and 10BASE-T speed make the device most suitable for systems that already rely on the AT/LANTIC environment; it is not a modern 100BASE-TX or gigabit Ethernet controller.
When replacing this component, engineers should verify the complete 160-pin footprint, exposed pad requirements, power rails, oscillator components, magnetics isolation, and legacy bus termination before substituting. Because this part is obsolete and few verified pin-compatible replacements are documented, board-level redesign to a current Ethernet controller may be safer than assuming equivalent availability.
Drop-in alternatives for DP83905AVQB — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
No drop-in alternatives available for this product.
Request AlternativesDP83905AVQB Specifications
| Controller Type | AT/LANTIC AT Local Area Network twisted-pair interface controller |
| Ethernet Standard | IEEE 802.3 |
| Physical Layer | 10BASE-T PHY |
| Host Interface | ISA |
| Supply Voltage Range | 4.75 V to 5.25 V |
| Supply Current | 100 mA |
| Operating Temperature Range | 0 °C to 70 °C |
| Temperature Grade | Commercial |
| Package Type | 160-BFQFP |
| Package Dimensions | 28 mm x 28 mm |
| Pin Count | 160 pins |
| Terminal Form | Gull wing |
| Package Shape | Square |
| Packaging | Tray |
| Lifecycle Status | Obsolete |
DP83905AVQB square Pin Configuration Guide
Pin configuration for DP83905AVQB (square package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for DP83905AVQB.
Refer to the datasheet for full pin configuration.
Typical Applications
DP83905AVQB is suitable for 6 applications: Legacy AT-Compatible Ethernet Adapter, Industrial Control System Network Retrofit, 10BASE-T Network Monitoring Terminal, Legacy Network Adapter Repair, Educational and Bench-Top Ethernet Demonstrator, Embedded Instrumentation with Legacy Bus.
Legacy AT-Compatible Ethernet Adapter
The DP83905AVQB fits an ISA-based AT-compatible Ethernet adapter that must reproduce the original AT/LANTIC behavior and connect to an existing 10BASE-T network. Its integrated IEEE 802.3 10BASE-T PHY removes the need for a separate physical-layer controller, while the verified 100 mA supply current and 4.75 V to 5.25 V supply range fit legacy 5 V logic budgets. The important engineering constraint is board-level replication: the 160-BFQFP footprint, timing, bus termination, line interface, and magnetics must all match the original design. Use this device for repair of installed cards rather than for new volume designs.
Recommended
Industrial Control System Network Retrofit
The DP83905AVQB can maintain an IEEE 802.3 10BASE-T connection in legacy industrial control or data-acquisition equipment whose backplane is based on the ISA interface and the AT/LANTIC protocol. The 0 °C to 70 °C commercial operating range covers ordinary factory environments, while the 5 V supply requirement simplifies integration with older control electronics. Because the controller is obsolete and limited to 10BASE-T, production planning should include obsolescence monitoring and a documented migration path. The practical benefit is restoring network communication without modifying the host CPU, software stack, and existing bus architecture.
Recommended
10BASE-T Network Monitoring Terminal
The DP83905AVQB is applicable to monitoring equipment that collects data from an existing 10BASE-T installation and exposes it through an AT-compatible bus. Its integrated 10BASE-T PHY handles the network physical layer while the controller manages frame-level AT/LANTIC activity. This reduces component count relative to a design that separates the network controller and PHY, and the verified IEEE 802.3 compliance keeps the interface aligned with existing 10BASE-T infrastructure. Engineers should still budget for line filtering, isolation, magnetics, and bus timing that are not quantified in the verified distributor data.
Recommended
Legacy Network Adapter Repair
The DP83905AVQB is most valuable as a repair component for a 160-pin legacy Ethernet adapter that has suffered controller failure. Installing the exact original MPN preserves the ISA pin assignment, AT/LANTIC protocol behavior, 10BASE-T PHY integration, and 4.75 V to 5.25 V supply expectations without a board respin. The obsolete lifecycle status makes procurement and condition verification the central risks: use authorized or specialist distributors, request traceability, and inspect the QFP for handling damage. Board-level testing should confirm supply rails, clock behavior, and magnetics isolation before returning the equipment to service.
Recommended
Educational and Bench-Top Ethernet Demonstrator
The DP83905AVQB supports educational bench demonstrations of how an AT/LANTIC controller, an ISA host interface, and an integrated IEEE 802.3 10BASE-T PHY operate together. Its 160-BFQFP package is large enough that hand-soldering is impractical, but it is well suited to a refurbished legacy adapter board with documented test points. The verified 100 mA supply current and single 5 V rail simplify instrumentation. Demonstrators should clearly note that the device operates only at 10BASE-T and that current controllers use different host interfaces, so the demonstration teaches legacy networking architecture rather than modern Ethernet design practice.
Recommended
Embedded Instrumentation with Legacy Bus
The DP83905AVQB can be used in an embedded acquisition chassis that must communicate through an inherited ISA/AT-compatible network path. Its integrated 10BASE-T PHY is advantageous when only a legacy expansion slot is available because it combines the controller and physical layer in one 160-pin device. The commercial 0 °C to 70 °C specification is adequate for controlled indoor instrumentation, and the 4.75 V to 5.25 V operating range aligns with older backplanes. Since no current price, pin-level data beyond the referenced PDF, or lifecycle roadmap was verified, production use should be restricted to long-term maintenance with a redesign contingency.
Recommended
Recommended Products Summary
Engineering reference data for DP83905AVQB — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product |
|---|---|
| Package | 160-BFQFP, 28 mm x 28 mm |
| Brand | Texas Instruments |
| Controller Type | AT/LANTIC twisted-pair interface controller |
| Ethernet Standard | IEEE 802.3 |
| Physical Layer | 10BASE-T PHY |
| Host Interface | ISA |
| Supply Voltage Range | 4.75 V to 5.25 V |
| Supply Current | 100 mA |
| Operating Temperature Range | 0 °C to 70 °C |
| Lifecycle Status | Obsolete |
Key Differentiators
- Integrated AT/LANTIC controller and 10BASE-T PHY (vs ENC28J60/SS)
- Legacy ISA connectivity (vs ENC28J60/ML)
- Single 5 V operating range (vs Modern compact Ethernet controllers)
- Exact legacy repair compatibility (vs DP83905AVQB/NOPB)
Design Notes
Do not treat the DP83905AVQB as a new-design component. Reproduction of an original board requires the exact 160-lead BFQFP footprint, pin numbering, solder-mask and paste-land geometry, and component placement around all four sides. Review the manufacturer datasheet PDF for the authoritative footprint and pin table before ordering a replacement PCB. The supplied data does not expose the exposed-pad requirement or recommended land pattern, so those details must not be inferred from the generic 28 mm x 28 mm package dimensions.
Design the 5 V supply rail around the verified 4.75 V to 5.25 V operating range and the listed 100 mA supply current. Place local high-frequency bypass capacitors at the device's supply pins and keep return-current paths short, following the decoupling arrangement in the manufacturer datasheet. The verified data does not state total board power, startup current, or per-pin current limits, so the available 100 mA figure should be treated as the listed device specification rather than a complete system power budget.
The ISA interface and network physical layer occupy very different signal environments. Route ISA address, data, and control traces away from the twisted-pair input section and maintain the clock and bus timing required by the original design. Preserve the line-interface component placement and filtered return paths shown in the reference schematic or datasheet application circuit. Do not substitute generic Ethernet magnetics or bias networks without checking impedance, isolation voltage, and the controller's original line-driver requirements.
The most common sourcing mistake is treating DP83905AVQB/NOPB as a different drop-in alternative. It appears in the cross-reference data as an ordering designation associated with the same DP83905AVQB controller, so it does not add an independent second-source option. Likewise, ENC28J60/SS and ENC28J60/ML are suitable architectural references for a redesigned Ethernet interface, but they are not pin-to-pin replacements for the 160-lead ISA controller. Verify the exact device marking, package condition, and provenance before installation.
Compliance Information
The verified sources describe the legacy National Semiconductor DP83905 controller and do not provide RoHS, REACH, halogen-free, lead-free, conflict-minerals, or AEC-Q100 declarations. AEC-Q100 is not applicable to the listed commercial-grade part, but the remaining compliance fields remain unknown rather than assumed.
