Texas Instruments SN65ELT22DR

Overview

SN65ELT22DR from Texas Instruments is a dual TTL-to-differential PECL translator operating on a single +5-V supply (4.2 V to 5.7 V), delivering 1.1-ns max propagation delay, <50-ps typ output-to-output skew, and PECL output levels (VOH = 3915–4120 mV, VOL = 3170–3380 mV) with 500-MHz max switching frequency. It serves in high-speed clock/data transmission over backplanes and signaling-level conversion for timing-critical systems.

For engineers reviewing the SN65ELT22DR datasheet, SN65ELT22DR pinout, SN65ELT22DR application, or SN65ELT22DR equivalent, key selection criteria include its SOIC-8 package compatibility, TTL input interface (VIH = 2.0 V, VIL = 0.8 V), differential PECL output drive capability, thermal performance (θJA = 79°C/W), and drop-in functional equivalence to MC10ELT22/MC100ELT22 in legacy designs.

Technical Context

The SN65ELT22DR implements two independent TTL-to-PECL translation channels with matched internal delay paths, enabling precise synchronization of dual clock or data streams. Its built-in temperature compensation maintains stable DC output levels across –40°C to 85°C, while termination at VCC – 2.0 V into 50-Ω loads ensures compliant PECL signal integrity.

Each channel accepts standard TTL logic inputs (D0/D1) and drives complementary PECL outputs (Q0/Q0, Q1/Q1) with rail-to-rail swing referenced to VCC. The device requires no external biasing and exhibits low device-to-device skew (≤100 ps) under identical VCC conditions, supporting deterministic timing in multi-channel backplane interconnects.

Key Specifications

Pinout & Package

SN65ELT22DR is housed in an industry-standard SOIC-8 (D) package (5.05 mm × 3.95 mm × 1.75 mm max height), RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar TTL-to-PECL translation applications.

Compared with MC10ELT22 and SN65ELT21DR, the SN65ELT22DR provides dual-channel functionality in TI's actively supported production line, tighter thermal resistance (θJA = 79°C/W), and guaranteed MSL-1 reliability-making it optimal for new industrial and telecom designs requiring long-term supply continuity and validated performance.

Availability

SN65ELT22DR is available at Aetrix Electronics and suitable for backplane clock distribution, high-speed data bus translation, and FPGA-to-ASIC interface bridging requiring stable component supply, full traceability, and long-lifecycle support.

Supply support for SN65ELT22DR 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 connectivity technologies, with decades of expertise in high-speed interface ICs and precision timing solutions.

The SN65ELT22DR belongs to TI's high-speed logic translator product line, engineered specifically for reliable TTL-to-PECL signal conversion in telecom infrastructure, industrial automation, and test equipment where deterministic timing and noise immunity are essential.

FAQ

What is the recommended termination for SN65ELT22DR PECL outputs?

The SN65ELT22DR PECL outputs (Q0, Q0, Q1, Q1) must be terminated with a 50-Ω resistor to VCC – 2.0 V. This configuration ensures correct DC biasing and differential signal integrity. Using alternative terminations-such as AC coupling or unterminated lines-will cause undefined output states or excessive jitter. The SN65ELT22DR datasheet Figure 1 explicitly defines this termination scheme as mandatory for compliance with PECL standards.

Does SN65ELT22DR support operation below 4.2 V?

No, SN65ELT22DR is not specified or guaranteed for operation below 4.2 V. Its absolute minimum supply voltage is 4.2 V, and all AC/DC parameters-including propagation delay, output voltage levels, and skew-are characterized only within the 4.2 V to 5.7 V range. Operating SN65ELT22DR at 3.3 V or other non-compliant rails will result in undefined behavior, including potential failure to meet timing specs or output instability.

Can SN65ELT22DR drive 100-Ω differential transmission lines directly?

No, SN65ELT22DR is designed for 50-Ω single-ended termination to VCC – 2.0 V-not 100-Ω differential lines. Its output stage lacks internal 100-Ω differential impedance; attempting direct connection to 100-Ω lines causes mismatched termination, degraded rise/fall times, and increased jitter. To interface with 100-Ω differential receivers, external resistive networks or dedicated PECL-to-LVDS translators are required alongside SN65ELT22DR.

Is SN65ELT22DR pin-compatible with SN65ELT22DGK?

Yes, SN65ELT22DR (SOIC-8) and SN65ELT22DGK (VSSOP-8) share identical pin functions and ordering logic, but differ in physical package dimensions and thermal characteristics. While both use the same pin numbering and assignment (D0/D1, Q0/Q0, Q1/Q1, VCC, GND), the SOIC-8 body (5.05 mm × 3.95 mm) is larger than VSSOP-8 (3.0 mm × 3.0 mm), and θJA differs (79°C/W vs. 213°C/W). Layout changes are required for package substitution, though schematic connectivity remains unchanged.

What is the maximum junction temperature for continuous operation of SN65ELT22DR?

The maximum junction temperature for continuous operation of SN65ELT22DR is 125°C, derived from its rated operating ambient temperature (–40°C to +85°C) and thermal resistance θJA = 79°C/W. At 2500-unit tape-and-reel volume and 20 mA typical ICC, power dissipation remains ≤100 mW, keeping TJ well below 125°C under standard board airflow (>500 lfpm). Exceeding 125°C risks permanent parametric shift or latch-up, as confirmed in the SN65ELT22DR Absolute Maximum Ratings table.