Texas Instruments DS92LV1021TMSA/NOPB

Overview

DS92LV1021TMSA/NOPB from Texas Instruments (formerly National Semiconductor) is a 10-bit parallel-to-serial LVDS serializer IC designed for high-reliability backplane and cable data transmission. It accepts 10-bit CMOS/TTL parallel data at 16–40 MHz clock rates, embeds clock via start/stop bits, outputs single-pair Bus LVDS at up to 480 Mbps serial rate (400 Mbps payload), and supports TRI-STATE output control and powerdown mode. It is used in industrial backplanes, medical imaging subsystems, and test equipment where skew elimination and robust differential signaling are critical.

For engineers reviewing the DS92LV1021TMSA/NOPB datasheet, DS92LV1021TMSA/NOPB pinout, DS92LV1021TMSA/NOPB application, or DS92LV1021TMSA/NOPB equivalent, key selection considerations include its guaranteed transition per cycle, flow-through SSOP-28 pinout, 27 Ω Bus LVDS drive capability, synchronization lock timing (≤2049 TCLK cycles), and compatibility with heavily loaded multi-drop buses up to 10 meters.

Technical Context

The DS92LV1021TMSA/NOPB implements a PLL-based serialization architecture that embeds clock information using dedicated start (high) and stop (low) bits framing each 10-bit word-forming a deterministic 12-bit serial cycle. Its internal PLL locks to TCLK in 2048–2049 cycles and supports programmable rising/falling edge sampling via TCLK_R/F.

It operates in three active states (Initialization, Data Transfer, Resynchronization) and two passive states (Powerdown, TRI-STATE), with explicit control over DEN (output enable), PWRDN (powerdown), and dual SYNC inputs for lock initiation and recovery. The Bus LVDS output complies with 27 Ω load rating and delivers 200–270 mV differential voltage with <35 mV unbalance.

Key Specifications

Pinout & Package

DS92LV1021TMSA/NOPB is housed in a 28-lead Small Outline Plastic Package (SSOP), designated MSA28 by National Semiconductor. This package features gull-wing leads, 0.635 mm lead pitch, and thermal characteristics supporting 1.27 W max dissipation at 25°C with 10.2 mW/°C derating above ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serializer applications.

Compared with DS92LV1021TMSA/NOPB, DS92LV1023TMA/NOPB offers higher bandwidth but requires package and timing redesign, while SN65LV1023PWR delivers identical performance with enhanced reliability and lifecycle support-making it the recommended drop-in alternative for new production.

Availability

DS92LV1021TMSA/NOPB is available at Aetrix Electronics and suitable for industrial backplane interfaces, medical imaging subsystems, and test equipment requiring stable component supply, long-term obsolescence management, and traceable sourcing from authorized channels.

Supply support for DS92LV1021TMSA/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 full technical and supply chain support for legacy National products including the DS92LV1021TMSA/NOPB.

This device belongs to TI's legacy high-speed interface portfolio, originally developed for deterministic, low-skew data transport across noisy industrial and medical backplanes using Bus LVDS technology.

FAQ

What is the maximum serial data rate supported by DS92LV1021TMSA/NOPB?

The DS92LV1021TMSA/NOPB supports a maximum serial data rate of 480 Mbps, achieved when operating at its upper clock limit of 40 MHz (12 × 40 MHz). Its usable payload rate is 400 Mbps (10 × 40 MHz), as two bits per 12-bit frame are reserved for embedded clocking (start and stop bits). This rate is sustained across its full 16–40 MHz TCLK range with verified timing margins per the datasheet.

Does DS92LV1021TMSA/NOPB require an external oscillator or reference clock?

No, DS92LV1021TMSA/NOPB does not require an external oscillator or reference clock. It uses the incoming TCLK signal (16–40 MHz) as both data sampling clock and PLL reference. In contrast, its companion deserializer DS92LV1210 requires REFCLK for PLL operation-but the DS92LV1021TMSA/NOPB itself derives all timing internally from TCLK.

How does DS92LV1021TMSA/NOPB handle power-up sequencing to avoid output lockup?

To prevent Bus LVDS output lockup, DS92LV1021TMSA/NOPB must be powered with all VCC pins stabilized simultaneously while holding PWRDN low for ≥1 µs. Floating PWRDN is prohibited; an external pull-down resistor is recommended. If lockup occurs (e.g., TCLK applied before VCC), cycling PWRDN high→low→high resets the PLL without power cycling-restoring normal DS92LV1021TMSA/NOPB operation.

Can DS92LV1021TMSA/NOPB drive a multi-drop bus, and what termination is required?

Yes, DS92LV1021TMSA/NOPB is explicitly designed for multi-drop Bus LVDS buses. It drives 27–100 Ω differential loads and supports up to ~20 deserializers. For multi-drop operation, the bus must be terminated at both ends (e.g., 100 Ω differential at each end), resulting in a net DC load near 27 Ω-within DS92LV1021TMSA/NOPB's specified drive capability.

What is the function of the SYNC1 and SYNC2 pins on DS92LV1021TMSA/NOPB?

The SYNC1 and SYNC2 pins on DS92LV1021TMSA/NOPB are OR'd inputs that, when asserted high for ≥1024 TCLK cycles, command the device to transmit synchronization patterns (six 1s followed by six 0s). These patterns enable the companion deserializer (e.g., DS92LV1210) to achieve and maintain lock to the embedded clock-critical for initialization and resynchronization after loss-of-lock events.