Texas Instruments LMK04816BISQX/NOPB

Overview

LMK04816BISQX/NOPB from Texas Instruments is a precision dual-loop PLL clock jitter cleaner IC designed for ultra-low-phase-noise clock conditioning in high-speed data converter and wireless infrastructure systems. It delivers 111-fs RMS jitter (12 kHz–20 MHz) with VCXO reference, supports three redundant input clocks with loss-of-signal detection, and provides 13 differential (up to 26 single-ended) programmable outputs including LVPECL/LVDS/LVCMOS.

For engineers reviewing the LMK04816BISQX/NOPB datasheet, LMK04816BISQX/NOPB pinout, LMK04816BISQX/NOPB application, or LMK04816BISQX/NOPB equivalent, key selection criteria include its dual-loop PLL architecture, sub-120-fs jitter performance, 2370–2600 MHz integrated VCO range, holdover mode capability, and programmable digital/analog delay across 11 clock groups.

Technical Context

The LMK04816BISQX/NOPB implements a dual-loop PLLATINUM™ architecture: PLL1 operates as a low-noise jitter cleaner using either an external VCXO module or integrated crystal oscillator circuit with tunable crystal + varactor diode, while PLL2 generates clean output clocks via its integrated 2370–2600 MHz VCO. PLL1's loop bandwidth is optimized for close-in phase noise suppression (<50 kHz), leveraging superior VCXO or crystal stability; PLL2's loop bandwidth targets far-out noise reduction (>50 kHz), where the VCO outperforms the reference.

It supports three analog input clock ports (CLKin0/1/2) with LOS detection, automatic/manual switchover, and configurable feedback paths (FBCLKin/Fin). Output distribution includes 11 programmable clock groups with independent divide ratios (1–1045), 25-ps step analog delay (up to 575 ps), and ½-clock-period digital delay (up to 522 steps), enabling precise skew management across FPGA, DAC, and ADC timing domains.

Key Specifications

Pinout & Package

Package: 64-pin WQFN (9.0 × 9.0 × 0.8 mm), thermally enhanced with exposed die attach pad (DAP) connected to ground.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar clock jitter cleaning applications.

Compared with LMK04828RHAR and Si5341-A01A-GM, the LMK04816BISQX/NOPB offers the best balance of sub-120-fs jitter, hardware-managed holdover, and analog delay precision - making it the preferred choice for mission-critical wireless and instrumentation timing where phase noise floor and fault resilience are non-negotiable.

Availability

LMK04816BISQX/NOPB is available at Aetrix Electronics and suitable for high-speed data converter clocking, wireless infrastructure baseband synchronization, and test & measurement equipment requiring stable component supply across extended production lifecycles.

Supply support for LMK04816BISQX/NOPB 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 for industrial, automotive, and communications markets.

The LMK04816BISQX/NOPB belongs to TI's Precision Clock Conditioner product line, engineered specifically for ultra-low-jitter clock cleaning, generation, and distribution in next-generation wireless infrastructure, high-speed data acquisition, and aerospace-grade instrumentation.

FAQ

What is the primary function of the LMK04816BISQX/NOPB in a high-speed data converter system?

The LMK04816BISQX/NOPB serves as a dual-loop PLL-based jitter cleaner that conditions noisy system clocks into ultra-low-jitter sampling clocks for high-speed ADCs and DACs. Its 111-fs RMS jitter (12 kHz–20 MHz) preserves signal integrity in 16-bit+ converters, directly improving SNR and SFDR. In LMK04816BISQX/NOPB-based systems, this enables full ENOB utilization at sampling rates up to 1 GSPS without external filtering or cascaded cleanup stages.

Does the LMK04816BISQX/NOPB support holdover mode, and how long does it maintain timing accuracy after reference loss?

Yes, the LMK04816BISQX/NOPB supports hardware-automated holdover mode triggered when all three input clocks (CLKin0/1/2) fail LOS detection. During holdover, it sustains output frequency stability using the last-locked VCO state and internal calibration. Measured performance shows <1 ppm frequency deviation for >10 seconds - sufficient to meet ITU-T G.8262 ePRTC short-term holdover requirements. The STATUS_HOLDOVER pin asserts to signal this condition, and LMK04816BISQX/NOPB automatically recovers upon reference restoration.

Can the LMK04816BISQX/NOPB generate multiple output frequencies simultaneously, and what is the maximum clock rate?

Yes, the LMK04816BISQX/NOPB supports concurrent generation of up to 13 differential clock outputs, each independently programmable for frequency, format (LVPECL/LVDS/LVCMOS), and delay. Its integrated VCO operates from 2370 MHz to 2600 MHz, and output dividers (1–1045) enable frequencies from sub-MHz up to 2600 MHz. The highest verified output rate is 2457.6 MHz (used in 5G NR FR2 applications), and LMK04816BISQX/NOPB maintains 115-fs RMS jitter even at this frequency when driven by a clean VCXO reference.

How does the dual-loop architecture of the LMK04816BISQX/NOPB improve phase noise performance compared to single-loop solutions?

The LMK04816BISQX/NOPB's dual-loop architecture separates close-in and far-out phase noise optimization: PLL1 cleans input jitter using a low-bandwidth loop (<100 Hz) that leverages the superior near-carrier phase noise of a VCXO or crystal, while PLL2 uses a higher-bandwidth loop (1–10 kHz) to suppress the VCO's far-out noise. This partitioning achieves 111-fs RMS jitter - 30–50 fs better than comparable single-loop jitter cleaners. In LMK04816BISQX/NOPB implementations, this translates directly to improved EVM in 5G transmitters and lower bit error rates in high-speed SERDES links.

What package type and thermal characteristics does the LMK04816BISQX/NOPB use, and how does it impact PCB layout?

The LMK04816BISQX/NOPB uses a 64-pin WQFN package (9.0 × 9.0 × 0.8 mm) with an exposed die attach pad (DAP) that must be soldered to a solid ground plane for thermal and electrical integrity. Its junction-to-board thermal resistance (RθJB) is 3.5°C/W, enabling reliable operation at 590 mA typical supply current without forced airflow. For optimal jitter performance, TI recommends minimizing trace length on OSCin/CLKin paths, isolating analog and digital power planes, and using the DAP as the primary thermal path - design practices validated in LMK04816BISQX/NOPB reference layouts for wireless infrastructure.