Texas Instruments SN65LVDT122DG4

Overview

SN65LVDT122 from Texas Instruments is a 1.5-Gbps 2×2 LVDS crosspoint switch with integrated 110-Ω termination resistors, designed for high-speed signal routing in optical modules and clock distribution systems. It supports LVDS, LVPECL, and CML inputs across 0–4 V common-mode range, delivers <65 ps peak-to-peak jitter at 1.5 Gbps, and operates from –40°C to 85°C on 3.3 V supply.

For engineers reviewing the SN65LVDT122 datasheet, SN65LVDT122 pinout, SN65LVDT122 application, or SN65LVDT122 equivalent, key selection criteria include differential input hysteresis (25 mV), propagation delay (≤900 ps), output skew (<40 ps), termination integration, and compatibility with fault-tolerant serial backplane protection switching.

Technical Context

The SN65LVDT122 implements a fully differential 2×2 crosspoint architecture with dual enable (1DE/2DE) and dual select (S0/S1) logic control, enabling dynamic reconfiguration between crosspoint, 2:1 MUX, 1:2 splitter, or dual repeater modes. Its internal signal paths preserve LVDS integrity without level translation.

It features electrically compatible inputs accepting LVDS (±100 mV threshold), LVPECL, and CML signals, and outputs compliant with ANSI/TIA/EIA-644 LVDS standards. The integrated 110-Ω termination eliminates external resistors on the receiver side, reducing board space and parasitic effects.

Key Specifications

Pinout & Package

SN65LVDT122 is available in 16-pin SOIC (D) and TSSOP (PW) packages. Both packages feature identical pin mapping and thermal ratings (–40°C to 85°C). The TSSOP variant offers smaller footprint (5.0 × 4.4 mm) and improved high-frequency layout control.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LVDS crosspoint switch applications.

Compared with SN65LVDS122, SN65LVDT122 reduces component count and layout complexity via integrated termination, while MAX9152 trades interface flexibility for broader voltage operation-neither is pin-compatible, requiring PCB redesign.

Availability

SN65LVDT122 is available at Aetrix Electronics and suitable for optical module manufacturing, wireless basestation development, and high-reliability serial backplane systems requiring stable component supply across extended production lifecycles.

Supply support for SN65LVDT122 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 is a global semiconductor leader specializing in analog, embedded processing, and high-speed interface solutions with over 50 years of innovation in signal integrity and timing products.

The SN65LVDT122 belongs to TI's LVDS interface portfolio, engineered specifically for high-bandwidth, low-jitter signal routing in telecom infrastructure, optical networking, and wireless communications equipment.

FAQ

What is the maximum supported data rate for SN65LVDT122?

The SN65LVDT122 is characterized for operation up to 1.5 Gbps using a 2²³−1 PRBS pattern, with total peak-to-peak jitter specified at <65 ps. While some 2-Gbps operation may be achievable under ideal loading and signal quality conditions, TI guarantees full specification compliance only at ≤1.5 Gbps. The SN65LVDT122 datasheet confirms this rating under recommended operating conditions (V_CC = 3.3 V, T_A = –40°C to 85°C).

Does SN65LVDT122 require external termination resistors?

No, SN65LVDT122 integrates 110-Ω termination resistors on-chip for both differential input pairs, eliminating the need for external resistors. This is confirmed in the device description ("LVDT Integrates 110-Ω Terminating Resistor") and electrical characteristics table (R_T = 90–132 Ω). In contrast, the pin-compatible SN65LVDS122 requires external termination, making SN65LVDT122 preferable for space-constrained designs.

Can SN65LVDT122 interface directly with LVPECL and CML sources?

Yes, SN65LVDT122 accepts LVPECL and CML inputs due to its wide 0–4 V common-mode input voltage range and differential input threshold hysteresis of 25 mV. The datasheet explicitly states "Inputs Electrically Compatible With CML, LVPECL and LVDS Signal Levels" and provides application circuits for all three standards (Figures 23–26). No level-shifting circuitry is required when connecting to standard LVPECL (V_TT = V_CC − 2 V) or CML drivers.

What configuration modes does SN65LVDT122 support via S0 and S1 pins?

SN65LVDT122 supports four routing configurations controlled by S0 and S1: 2×2 crosspoint switch, 2:1 input multiplexer, 1:2 output splitter, and dual repeater/translator. The functional truth table (page 4) defines each mode-for example, S0=L/S1=H configures 1A→1Y and 2A→2Y (splitter), while S0=H/S1=H enables full crosspoint (1A→2Y, 2A→1Y). All modes operate simultaneously with <2.6 ns select-to-output delay.

Is SN65LVDT122 pin-compatible with earlier TI LVDS switches?

Yes, SN65LVDT122 is pin-compatible with SN65LVDS22 and SN65LVDM22, serving as a speed-upgrade path to 1.5 Gbps. The datasheet states "Pin-Compatible With SN65LVDS22 and SN65LVDM22" and confirms identical pin assignments (16-pin SOIC/TSSOP). However, SN65LVDT122 adds integrated termination and tighter jitter specs-no PCB changes are needed for drop-in replacement in existing footprints.