Texas Instruments USBN9603SLB/NOPB

Overview

USBN9603SLB/NOPB from National Semiconductor is a full-speed USB 1.1 node controller IC integrating transceiver, 3.3V regulator, Serial Interface Engine (SIE), seven endpoint FIFOs (1×8-byte control + 6×64-byte data), 8-bit parallel/MICROWIRE interface, and enhanced DMA engine. It operates from 5V or 3.3V supply, supports 24 MHz crystal input with internal 48 MHz PLL clock generation, and targets embedded USB peripheral designs requiring low-EMI, bus-powered operation.

For engineers reviewing the USBN9603SLB/NOPB datasheet, USBN9603SLB/NOPB pinout, USBN9603SLB/NOPB application, or USBN9603SLB/NOPB equivalent, key selection criteria include its dual-mode CPU interface (multiplexed/non-multiplexed), automatic DMA (ADMA) for CPU-independent bulk/ISO transfers, programmable interrupt polarity, and 28-pin CSP package optimized for portable systems.

Technical Context

The USBN9603SLB/NOPB implements a complete USB 1.1-compliant Physical Layer (PHY) and Media Access Controller (MAC), including NRZI decoding, bit stuffing/unstuffing, CRC generation/checking, and clock recovery from 48 MHz derived from a 24 MHz oscillator. Its SIE handles all USB protocol states-NodeReset, NodeSuspend, NodeResume-and generates ACK/NAK/STALL handshakes under EPC control.

Endpoint Pipe Controller (EPC) manages seven dedicated pipes: one bidirectional control endpoint (EP0) and six unidirectional endpoints (three TX, three RX), each with independent FIFO, status, and command registers. The ADMA mode enables autonomous transfer of up to 16 KB (256 × 64-byte packets) without CPU intervention, with automatic PID toggling and NAK recovery.

Key Specifications

Pinout & Package

USBN9603SLB/NOPB uses a 28-pin Chip Scale Package (CSP) with 0.5 mm pitch, designed for compact portable applications. Pin functions are validated per National Semiconductor SNOS528L Rev 1.3 (June 2003).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB node controller applications.

Compared with USBN9604SLB/NOPB, the USBN9603SLB/NOPB offers identical feature set and package but simpler reset behavior-ideal for cost-sensitive, non-DLL-dependent designs. Versus CP2102-GM, it provides full USB function controller flexibility at the expense of higher integration effort, enabling custom class development and deterministic DMA-controlled data paths.

Availability

USBN9603SLB/NOPB is available at Aetrix Electronics and suitable for industrial data loggers, medical diagnostic tools, USB peripheral adapters, and point-of-sale terminals requiring stable component supply across extended product lifecycles.

Supply support for USBN9603SLB/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

National Semiconductor was a U.S.-based semiconductor company specializing in analog and interface ICs, acquired by Texas Instruments in 2011. Its legacy USB controllers remain widely deployed in industrial and medical equipment.

The USBN9603SLB/NOPB belongs to National's USB Node Controller family, designed specifically for embedded systems needing full-speed USB device functionality with minimal external components and flexible host interface options.

FAQ

What USB specification versions does the USBN9603SLB/NOPB support?

The USBN9603SLB/NOPB supports USB Specification versions 1.0 and 1.1 only-it is a full-speed (12 Mbps) node controller and does not support USB 2.0 High-Speed (480 Mbps) or later revisions. Its SIE implements all required protocol layers including bit stuffing, CRC checking, and handshake generation per USB 1.1 Chapter 8. The USBN9603SLB/NOPB remains fully compliant for legacy and cost-optimized full-speed peripheral designs.

Does the USBN9603SLB/NOPB require an external crystal, or can it use an external clock source?

The USBN9603SLB/NOPB supports both configurations: a 24 MHz fundamental crystal connected between XIN and XOUT, or an external 24 MHz clock applied to XIN with XOUT left unconnected. The internal oscillator circuit is optimized for AT-cut crystals with ≤50 Ω series resistance and 20 pF load capacitance. Using an external clock avoids crystal layout sensitivity but requires clean, low-jitter signal routing to maintain USB timing compliance. The USBN9603SLB/NOPB derives all internal clocks-including 48 MHz for the SIE and 12 MHz recovered clock-from this 24 MHz source.

How does the ADMA mode in the USBN9603SLB/NOPB reduce CPU overhead during USB transfers?

The USBN9603SLB/NOPB's Automatic DMA (ADMA) mode enables fully autonomous data movement between endpoint FIFOs and system memory without CPU intervention. Once configured, the ADMA engine handles 64-byte packet segmentation, PID toggling, NAK recovery (up to 256 packets = 16 KB), and endpoint status updates. This eliminates per-packet register polling and buffer management, freeing the host MCU for real-time tasks. The USBN9603SLB/NOPB's ADMA is especially valuable for isochronous or high-throughput bulk transfers where deterministic latency and low CPU utilization are critical.

Can the USBN9603SLB/NOPB operate from a 3.3 V supply only, without using the internal voltage regulator?

Yes-the USBN9603SLB/NOPB supports pure 3.3 V operation. In this mode, the internal 3.3 V regulator is disabled, and the V3.3 pin becomes an input supplying the transceiver directly. An external 3.3 V source must drive V3.3 (with 1 µF decoupling), while VCC is tied to the same 3.3 V rail. The transceiver's D+ pull-up resistor must then be connected to this external 3.3 V source. This configuration eliminates regulator dropout and thermal concerns, making the USBN9603SLB/NOPB suitable for low-power, single-rail 3.3 V systems where efficiency and simplicity are prioritized.

What is the purpose of the MODE1 and MODE0 pins on the USBN9603SLB/NOPB?

The MODE1 and MODE0 pins on the USBN9603SLB/NOPB configure the host interface mode at power-up: 00 selects non-multiplexed parallel (separate A0 and D7–D0), 01 selects multiplexed parallel (ALE and AD7–AD0, Intel-compatible), and 10 selects MICROWIRE/PLUS serial (SK/SI/SO). These pins are sampled during reset and cannot be changed dynamically. They allow one USBN9603SLB/NOPB silicon die to interface with diverse host processors-from 8051 microcontrollers to DSPs-without redesigning the PCB layout or adding glue logic. The USBN9603SLB/NOPB's flexibility here reduces BOM count and accelerates prototyping across multiple platform families.