Texas Instruments DP83902AVJG/NOPB

Overview

DP83902AVJG/NOPB from Texas Instruments (formerly National Semiconductor) is a single-chip IEEE 802.3-compliant Serial Network Interface Controller (ST-NIC) integrating MAC, ENDEC, and 10BASE-T transceiver functions for twisted-pair Ethernet. It operates at 10 Mbit/s with Manchester encoding/decoding, supports dual 16-bit DMA channels, includes a 16-byte internal FIFO, and delivers full AUI interface compatibility - enabling direct integration into legacy industrial and embedded LAN nodes.

For engineers reviewing the DP83902AVJG/NOPB datasheet, DP83902AVJG/NOPB pinout, DP83902AVJG/NOPB application, or DP83902AVJG/NOPB equivalent, key selection considerations include its integrated 10BASE-T transceiver with link integrity detection, programmable squelch thresholds (via SQSEL), collision/heartbeat/jabber timing compliance, and support for both half-step and full-step transmit idle modes via SEL pin configuration.

Technical Context

The DP83902AVJG/NOPB implements a complete CSMA/CD media access control stack with hardware-accelerated packet handling: its NIC module performs physical/multicast/broadcast address filtering using hash-based multicast recognition and stores network statistics in dedicated registers. The ENDEC module recovers clock and data from Manchester-encoded 10 Mbps streams with ≤18 ns jitter tolerance and ≤5-bit lock time.

Its TPI transceiver module integrates smart receive squelch (dual-threshold selectable via SQSEL), polarity correction (POL output), link pulse generation/detection (GDLNK/LNKDIS), jabber timeout (26 ms disable), and digital pre-emphasis via resistively combined TXOa/TXOb/TXOda/TXOdb outputs - all meeting IEEE 802.3 10BASE-T electrical requirements without external precision components.

Key Specifications

Pinout & Package

The DP83902AVJG/NOPB is housed in a 100-pin Plastic Quad Flat Package (PQFP), designated NS package VJG100A, with 0.5 mm lead pitch and 14 mm × 14 mm body size. Pin assignments follow the AVJG variant layout per SNLS082A.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10BASE-T network interface controller applications.

Compared with DP83902AVJG/NOPB, the DP83902AVLJ/NOPB offers identical functionality in a different package for assembly flexibility, while the RTL8019AS trades advanced diagnostics and cabling adaptability for broader OS driver support and lower system cost - making it suitable for commodity PC networking rather than ruggedized embedded deployment.

Availability

DP83902AVJG/NOPB is available at Aetrix Electronics and suitable for industrial control network nodes, legacy PC LAN adapters, embedded diagnostic tools, and network test equipment requiring stable component supply across long-lifecycle programs.

Supply support for DP83902AVJG/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments acquired National Semiconductor in 2011 and maintains legacy product support, including obsolescence management and datasheet archives for historically significant interface ICs.

The DP83902AVJG/NOPB belongs to TI's legacy ST-NIC (Serial Network Interface Controller) family, designed specifically for cost-effective, single-chip 10BASE-T Ethernet implementation in resource-constrained embedded systems before the rise of integrated MAC+PHY SoCs.

FAQ

What is the primary function of the DP83902AVJG/NOPB in an Ethernet system?

The DP83902AVJG/NOPB serves as a complete IEEE 802.3-compliant Serial Network Interface Controller, integrating Media Access Control (MAC), Manchester ENDEC, and 10BASE-T transceiver functions into a single chip. It handles CSMA/CD arbitration, packet framing, CRC generation/checking, and physical-layer signaling - enabling direct connection to twisted-pair cabling without external PHY or ENDEC components. Its role is foundational to building compact, low-cost 10 Mbps Ethernet nodes.

Does the DP83902AVJG/NOPB require an external crystal or oscillator?

Yes, the DP83902AVJG/NOPB requires a 20 MHz timing source connected between X1 and X2 pins. It supports either a parallel-resonant AT-cut crystal (20 pF load, ≤25 Ω ESR) or an external 20 MHz clock applied to X1 with X2 grounded. This 20 MHz signal is internally divided to generate the 10 MHz transmit clock and ENDEC timing - critical for maintaining IEEE 802.3 ±0.01% frequency accuracy. The DP83902AVJG/NOPB does not contain an integrated oscillator circuit.

How does the DP83902AVJG/NOPB handle polarity reversal on twisted-pair cabling?

The DP83902AVJG/NOPB detects polarity reversal via its POL pin, which asserts high upon receipt of seven consecutive link pulses or three consecutive packets with inverted differential polarity. Internally, the TPI module corrects for this condition, allowing proper Manchester decoding without requiring rewiring. The latched POL state remains active until reset, and the corrected operation ensures interoperability with miswired 10BASE-T installations - a key reliability feature for field-deployed DP83902AVJG/NOPB systems.

What are the three loopback modes supported by the DP83902AVJG/NOPB?

The DP83902AVJG/NOPB supports three diagnostic loopback modes: (1) Internal loopback - routes ENDEC output directly to ENDEC input, bypassing transceiver; (2) Transceiver loopback - connects TPI transmitter output to TPI receiver input within the chip; and (3) External loopback - uses external cabling to route AUI or TPI output back to corresponding input. These modes enable staged validation of MAC logic, ENDEC functionality, and physical-layer signal integrity - essential for bring-up and failure analysis of DP83902AVJG/NOPB-based designs.

Can the DP83902AVJG/NOPB interface with media other than twisted-pair?

Yes, the DP83902AVJG/NOPB supports alternative media via its AUI (Attachment Unit Interface). When AUI/TPI SELECT (pin 75) is high, the chip routes ENDEC signals to differential AUI outputs (TXa/TXb) and inputs (RXa/RXb, CDb/CDa), enabling connection to external 10BASE5 (thick coax) or 10BASE2 (thin coax) transceivers. This dual-interface capability allows DP83902AVJG/NOPB to serve as a universal 10 Mbps MAC across multiple IEEE 802.3 physical layers - provided appropriate isolation (capacitive or inductive) is used for AUI differential signals.