Texas Instruments SN65LVEL11DGKR

Overview

SN65LVEL11DGKR from Texas Instruments is a fully differential 3.3 V ECL 1:2 fanout buffer with deterministic open-input behavior, 5 ps within-device output skew, 265 ps typical propagation delay, and support for clock frequencies exceeding 2.0 GHz. It operates in PECL mode (VCC = 3.0–3.8 V, VEE = 0 V) or NECL mode (VCC = 0 V, VEE = –3.0 to –3.8 V), and is used in high-speed clock distribution for telecom backplanes and FPGA timing interfaces.

For engineers reviewing the SN65LVEL11DGKR datasheet, SN65LVEL11DGKR pinout, SN65LVEL11DGKR application, or SN65LVEL11DGKR equivalent, key selection criteria include differential ECL/PECL compatibility, sub-300 ps propagation delay, built-in input pull-down resistors (75 kΩ), thermal resistance (θJB = 120 °C/W), and VSSOP-8 package suitability for dense PCB layouts.

Technical Context

The SN65LVEL11DGKR implements a fully differential ECL architecture with matched internal paths to guarantee ≤5 ps skew between Q0/Q1 outputs. Its input stage includes integrated 75 kΩ pull-down resistors that enforce a known LOW state during open or VEE-tied conditions, eliminating external biasing.

It supports dual-supply operation: PECL mode (VCC = 3.3 V ±0.3 V, VEE = 0 V) and NECL mode (VCC = 0 V, VEE = –3.3 V ±0.3 V), with all DC parameters scaling linearly with supply rails. Output termination requires 50 Ω to VCC – 2.0 V for PECL or to ground for NECL, per TI's recommended AC test setup.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package: 3.0 mm × 3.0 mm body, 1.1 mm max height, 0.65 mm lead pitch, exposed pad optional (not electrically connected per TI documentation). RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ECL/PECL fanout buffer applications.

Compared with SN65EL11D and MC100LVEL11DTG, the SN65LVEL11DGKR uniquely combines guaranteed open-input logic state, TI's validated VSSOP thermal performance (θJB = 120 °C/W), and large-volume tape-and-reel packaging - making it optimal for high-reliability, high-density clock distribution where layout space and supply-chain continuity are critical.

Availability

SN65LVEL11DGKR is available at Aetrix Electronics and suitable for telecom infrastructure, FPGA-based test equipment, and high-speed data acquisition systems requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across temperature.

Supply support for SN65LVEL11DGKR 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 precision timing and signal integrity.

The SN65LVEL11DGKR belongs to TI's LVEL family of ECL/PECL fanout buffers, designed specifically for ultra-low-skew, high-frequency clock distribution in telecom, computing, and instrumentation applications where deterministic timing behavior is mandatory.

FAQ

What is the recommended termination for SN65LVEL11DGKR outputs in PECL mode?

For PECL operation (VCC = 3.3 V, VEE = 0 V), each SN65LVEL11DGKR output must be terminated with a 50 Ω resistor to VCC – 2.0 V (i.e., 1.3 V). This matches the standard PECL termination scheme and ensures specified VOH/VOL levels (2.215–2.420 V / 1.470–1.680 V) and rise/fall times (150–300 ps). The SN65LVEL11DGKR datasheet Figure 1 explicitly defines this configuration.

Does SN65LVEL11DGKR support NECL operation, and what are the supply requirements?

Yes, SN65LVEL11DGKR supports NECL mode with VCC = 0 V and VEE = –3.0 V to –3.8 V. In this configuration, outputs swing between –1.085 V and –1.830 V (VOH/VOL), inputs accept –1.165 V to –1.810 V (VIH/VIL), and the internal pull-downs reference to VEE. All AC specs-including 2.9 GHz max frequency and 5 ps skew-apply identically, as confirmed in the LVPNECL DC and AC tables of the SN65LVEL11DGKR datasheet.

How does the built-in 75 kΩ input pull-down resistor affect SN65LVEL11DGKR system behavior?

The 75 kΩ pull-down on each SN65LVEL11DGKR input forces D and D to VEE when left unconnected or tied to VEE, resulting in deterministic LOW outputs. This eliminates metastability during power-up, hot-swap events, or source failure-critical in redundant clock systems. Unlike SN65EL11D, no external resistors are needed, saving board area and reducing BOM count while maintaining full ECL/PECL compatibility.

What is the thermal performance of SN65LVEL11DGKR in its VSSOP-8 package?

The SN65LVEL11DGKR in VSSOP-8 (DGK) has a junction-to-board thermal resistance (θJB) of 120 °C/W and junction-to-case (θJC) of 74 °C/W, per TI's PACKAGE OUTLINE documentation. At maximum ICC = 25 mA and TA = 85°C, power dissipation is ~82.5 mW (3.3 V × 25 mA), yielding a worst-case junction temperature rise of 9.9°C above board temperature-well within safe operating limits for industrial applications.

Is SN65LVEL11DGKR pin-compatible with MC10LVEL11 and SN65EL11 devices?

Yes, SN65LVEL11DGKR is drop-in compatible with MC10LVEL11 and functionally equivalent to SN65EL11, sharing identical SOIC-8 and VSSOP-8 pinouts, supply ranges, and AC timing. TI explicitly states "drop in compatible to MC10LVEL11, MC100LVEL11" and "functionally equivalent to SN65EL11 with improved performance" in the SN65LVEL11DGKR datasheet Feature section and Description block.