Texas Instruments LMK61E2-100M00SIAT

Overview

LMK61E2-100M00SIAT from Texas Instruments is an ultra-low-jitter LVPECL-output programmable oscillator delivering 100 MHz output with ±50 ppm total frequency tolerance, 90 fs RMS phase jitter (12 kHz–20 MHz), and robust –70 dBc PSRR across 50 kHz–1 MHz supply ripple. It operates from a single 3.3 V supply in industrial temperature range (–40°C to +85°C) and serves as a high-stability clock source for FPGA and processor reference timing in telecom infrastructure.

For engineers reviewing the LMK61E2-100M00SIAT datasheet, LMK61E2-100M00SIAT pinout, LMK61E2-100M00SIAT application, or LMK61E2-100M00SIAT equivalent, key selection criteria include its LVPECL output compatibility with high-speed SerDes interfaces, factory-programmed fixed-frequency operation, 6-pin QFM package footprint, and immunity to power supply noise in dense PCB layouts.

Technical Context

The LMK61E2-100M00SIAT integrates a high-performance PLL-based oscillator core with on-chip power conditioning to achieve ultra-low jitter and exceptional supply ripple rejection. Its architecture supports only LVPECL output format at this configuration (100 MHz), with differential pair OUTP/OUTN terminated internally to 150 Ω per leg for optimal signal integrity.

It features an LVCMOS OE input with internal pull-up, enabling hardware-controlled output enable/disable with 50 µs transition time, and uses a fixed-frequency, non-reprogrammable factory calibration-no I²C or SPI interface is present. The device is not a crystal or crystal oscillator replacement requiring external load capacitors; it is a fully integrated, self-contained clock module.

Key Specifications

Pinout & Package

The LMK61E2-100M00SIAT is housed in a 6-pin QFM (Quad Flat No-lead) package with exposed thermal pad, measuring 7.0 mm × 5.0 mm × 0.9 mm. The package is pin-compatible with standard 7050-format crystal oscillators, enabling drop-in replacement in existing layouts without footprint redesign.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-jitter oscillator applications.

Compared with LMK61E2-100M00SIAT, the SIAR variant offers identical performance in reel format for production lines, while the Si510 provides broader frequency flexibility but trades 35 fs of jitter margin-making the TI device preferable for next-gen high-speed serial interfaces demanding sub-100 fs stability.

Availability

LMK61E2-100M00SIAT is available at Aetrix Electronics and suitable for 10G/25G Ethernet line cards, FPGA-based compute accelerators, and medical imaging data acquisition systems requiring stable component supply with guaranteed long-term continuity.

Supply support for LMK61E2-100M00SIAT 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-performance timing solutions, with decades of expertise in clock generation and signal integrity.

The LMK61XX family was designed specifically for high-speed digital systems requiring ultra-low-jitter, supply-noise-immune clock sources-targeting telecom infrastructure, data center hardware, and precision instrumentation.

FAQ

Is the LMK61E2-100M00SIAT reprogrammable in-system?

No. This device is factory-programmed to 100 MHz LVPECL output and contains no I²C, SPI, or other configuration interface. It is a fixed-frequency oscillator-not a programmable clock generator. Reprogramming requires ordering a different part number (e.g., LMK61E2-125M00SIAT for 125 MHz).

What is the recommended power supply decoupling network?

Texas Instruments specifies three capacitors: 10 µF (bulk), 1 µF (mid-frequency), and 0.1 µF (high-frequency), all placed as close as possible to the VDD pin. Use 0201 or 0402 case sizes, mount on the component side, and connect each capacitor's ground pad directly to the PCB ground plane using short traces and multiple vias.

Can the OE pin be left floating?

No. OE has an internal pull-up but must be actively driven high (≥1.4 V) to enable outputs or low (≤0.6 V) to disable them. Leaving it floating risks metastability and unintended output toggling during power-up or noise events. Tie to VDD via 10 kΩ resistor if always enabled.

Does this device require external load capacitors like quartz crystals?

No. The LMK61E2-100M00SIAT is a fully integrated oscillator module with internal resonator and PLL. It requires no external load capacitors, crystal pads, or trimming components-only proper power decoupling and differential output termination (50 Ω to VDD–2 V for LVPECL).