Texas Instruments LMK61E2BBA-SIAT

Overview

LMK61E2BBA-SIAT from Texas Instruments is an ultra-low jitter (90 fs RMS typical @ >100 MHz), programmable oscillator with integrated fractional-N PLL, 4.6–5.6 GHz VCO, and factory-configured 125 MHz LVDS output. It features on-chip EEPROM for self-startup, I²C programmability, ±50 ppm total frequency tolerance, and operates from a single 3.3 V supply in industrial temperature range (–40°C to +85°C). Used as a high-stability clock source for FPGA and processor reference timing.

For engineers reviewing the LMK61E2BBA-SIAT datasheet, LMK61E2BBA-SIAT pinout, LMK61E2BBA-SIAT application, or LMK61E2BBA-SIAT equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative options with functional distinctions, and supply-chain support details specific to OEM and embedded system deployment.

Technical Context

The LMK61E2BBA-SIAT implements a fractional-N PLL architecture with integrated 4.6–5.6 GHz VCO and programmable output divider (5–511), enabling precise synthesis of 125 MHz LVDS from a 50 MHz crystal reference. Its dual-stage power conditioning includes dedicated LDOs for analog/digital domains, achieving –70 dBc PSRR across 50 kHz–1 MHz supply ripple frequencies.

Configuration is performed via I²C interface (100–400 kHz) with open-drain SCL/SDA, supporting runtime reprogramming and EEPROM write-back for persistent power-up defaults. Output enable (OE) and address select (ADD) pins provide hardware-level control over device activation and I²C target addressing without software intervention.

Key Specifications

Pinout & Package

LMK61E2BBA-SIAT uses a 7 mm × 5 mm, 8-pin QFM (SIA) package with exposed thermal pad. Pin 1 is ADD; pin 3 is GND; pin 6 is VDD; pins 4 and 5 are differential outputs (OUTP/OUTN); pin 8 is SCL; pin 7 is SDA; pin 1 is OE.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar programmable oscillator applications.

Compared with Si510-125.000M, LMK61E2BBA-SIAT trades fixed-frequency simplicity for full programmability and multi-format output; versus LMK62E2BBA-SIAT, it offers proven qualification at lower cost but with slightly higher jitter - making it optimal for volume industrial deployments where 90 fs meets spec and I²C configurability is essential.

Availability

LMK61E2BBA-SIAT is available at Aetrix Electronics and suitable for FPGA reference clocking, 5G baseband unit timing, and medical imaging signal processing requiring stable component supply across long-lifecycle industrial programs.

Supply support for LMK61E2BBA-SIAT 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 clock solutions, with decades of expertise in high-performance timing devices for communications and industrial markets.

The LMK61E2 product line delivers ultra-low jitter programmable oscillators targeting applications demanding precise, flexible, and robust clock generation - especially where system-level timing margin, supply noise immunity, and field-upgradable frequency settings are critical.

FAQ

What is the default output configuration of LMK61E2BBA-SIAT at power-up?

The LMK61E2BBA-SIAT is factory-programmed to output 125 MHz LVDS upon power-up, using its internal EEPROM to configure the PLL, output divider, and buffer mode without external programming. This self-start behavior occurs regardless of I²C bus state and is guaranteed across the full –40°C to +85°C temperature range.

Can LMK61E2BBA-SIAT generate frequencies other than 125 MHz?

Yes - through I²C programming, the device can synthesize any frequency from 10 MHz to 900 MHz in LVDS mode using its fractional-N PLL and 4.6–5.6 GHz VCO. The output divider (5–511) and feedback divider (integer + 22-bit fractional) allow precise step resolution down to sub-Hz levels, validated in TI's WEBENCH® Clock Architect tool.

How does the PSRR of –70 dBc impact system power design?

A –70 dBc PSRR means 50 mVpp supply ripple induces only ~5 µVpp spurious content in the 125 MHz LVDS output spectrum. This allows direct connection to buck converter outputs without additional LC filters, reducing bill-of-materials cost and PCB area while maintaining jitter performance within specification limits.

Is the SIA (QFM) package RoHS-compliant and lead-free?

Yes - the LMK61E2BBA-SIAT SIA package is RoHS-compliant and lead-free, qualified to J-STD-020 MSL3 moisture sensitivity level, and rated for standard Pb-free reflow profiles (peak 260°C). The exposed thermal pad is electrically connected to GND and must be soldered to a thermal land for proper thermal performance and mechanical reliability.