Texas Instruments SN65ELT23D

Overview

SN65ELT23D from Texas Instruments is a dual 5-V differential PECL-to-TTL translator IC used for level-shifting high-speed clock and data signals between PECL and TTL domains. It delivers 24-mA TTL outputs, supports up to 250 MHz switching frequency, exhibits 3.5-ns typical propagation delay, and features internal 50-kΩ pull-down resistors on PECL inputs-enabling robust operation in backplane signaling applications.

For engineers reviewing the SN65ELT23D datasheet, SN65ELT23D pinout, SN65ELT23D application, or SN65ELT23D equivalent, key selection criteria include its SOIC-8 package compatibility, guaranteed low-level output default under open-input conditions, built-in temperature compensation, and drop-in functional equivalence to MC100ELT23 in legacy designs.

Technical Context

The SN65ELT23D implements two independent PECL input stages with differential receivers and single-ended TTL output drivers, each with active-low logic polarity when inputs are unterminated. Its input common-mode range spans 2.2 V to 5.0 V, and it maintains stable DC thresholds across –40°C to 85°C ambient temperature.

AC performance is characterized at 5.0 V supply with 20 pF load and 500 Ω termination: propagation delay (tPLH/tPHL) is 2.0–5.0 ns, output rise/fall times are 1.0–3.0 ns / 0.5–1.6 ns, and random jitter is 3.7–10 ps RMS-making it suitable for synchronous clock distribution in telecom and industrial timing systems.

Key Specifications

Pinout & Package

SN65ELT23D is housed in an industry-standard SOIC-8 package (D package), 3.9 mm × 4.9 mm body size, 1.75 mm max height, with gull-wing leads and NiPdAu lead finish. Pin 1 is located at the top-left corner adjacent to the index area, per JEDEC MS-012AA outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC100ELT23DG and SN65ELT22D, the SN65ELT23D uniquely combines industrial temperature rating, dual-channel integration, and guaranteed drop-in compatibility-making it the optimal choice for new designs requiring reliability, density, and long-term supply continuity.

Availability

SN65ELT23D is available at Aetrix Electronics and suitable for backplane clock distribution, FPGA-to-ASIC interface, and industrial PLC timing modules requiring stable component supply and long-lifecycle support.

Supply support for SN65ELT23D 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 experience in high-speed interface and timing solutions.

The SN65ELT23D belongs to TI's high-speed logic translator product line, designed specifically for robust, low-jitter signal conditioning between differential PECL and single-ended TTL domains in industrial and communications infrastructure.

FAQ

What is the maximum operating frequency supported by the SN65ELT23D?

The SN65ELT23D supports a maximum switching frequency of 250 MHz under specified load conditions (RL = 500 Ω, CL = 20 pF). This value is verified across the full –40°C to +85°C temperature range and at VCC = 5.0 V. Performance remains stable up to this frequency with VOH ≥ 2.4 V and VOL ≤ 0.5 V, making SN65ELT23D suitable for high-speed clock distribution and data transmission applications.

Does the SN65ELT23D require external pull-down resistors on its PECL inputs?

No, the SN65ELT23D does not require external pull-down resistors. It integrates internal 50-kΩ pull-down resistors on all PECL inputs (D0, D0, D1, D1), ensuring a defined logic-low state when inputs are left open or driven below 1.3 V. This feature eliminates external components and simplifies board design-particularly beneficial in backplane and hot-swap applications where input floating is possible.

Is the SN65ELT23D pin-compatible with the MC100ELT23?

Yes, the SN65ELT23D is drop-in compatible with the MC100ELT23, sharing identical pin assignments, electrical specifications, and functional behavior. Both devices use SOIC-8 packaging with matching pin 1 location and terminal functions. The SN65ELT23D extends qualification to –40°C to +85°C, whereas MC100ELT23 is typically rated to +70°C-making SN65ELT23D a direct upgrade for industrial deployments.

What is the typical propagation delay of the SN65ELT23D, and how does it vary with temperature?

The SN65ELT23D has a typical propagation delay of 3.5 ns at 25°C, with a guaranteed range of 2.0 ns to 5.0 ns across the full operating temperature range (–40°C to +85°C). This variation is tightly controlled due to built-in temperature compensation circuitry, ensuring predictable timing margins in precision clocking applications regardless of thermal environment.

Can the SN65ELT23D drive standard TTL loads directly without additional buffering?

Yes, the SN65ELT23D can drive standard TTL loads directly. Its TTL outputs deliver 24 mA sink current and maintain VOH ≥ 2.4 V and VOL ≤ 0.5 V under full load, meeting LS-TTL and standard TTL input thresholds. Each output can drive up to 10 LS-TTL loads or 20 CMOS loads, eliminating the need for external buffers in most interface scenarios involving the SN65ELT23D.