MK2049-45SI - 51.84MHz Dual PLL Clock Synthesizer | Renesas

8 kHz Communications Clock Generation

The MK2049-45SI fits 8 kHz-locked communications timing because the Renesas device supports a communications-clock input of 8 kHz and provides 14 selectable output frequencies up to 51.84 MHz. It is used as a PLL-based clock synthesizer when a system must derive a stable operating reference from a narrow-band communications source rather than relying only on a free-running oscillator. The VCXO-based first PLL can track signal wander while attenuating input jitter, which is valuable when phase variation would otherwise propagate into downstream logic. During implementation, engineers must select the required output from the datasheet frequency table, establish the prescribed loop filter, and confirm the pullable-crystal configuration. The 3.3 V supply and 20-pin SOIC package support compact communications hardware, although the exact output frequency list and jitter limits require confirmation from the manufacturer document.

High-Frequency Clock Buffering

The MK2049-45SI can serve in high-frequency clock distribution when the source data's 125 MHz input condition applies and the selected output remains within the verified 51.84 MHz maximum-output limit. The device's second operating path supports high-frequency clock buffering and jitter attenuation, while two selectable buffer modes provide configuration flexibility. This use is appropriate where a communications subsystem needs a cleaner local clock or a controlled distribution point without introducing another clock-source topology. Designers should distinguish the 125 MHz input capability from the maximum output rating, calculate the required output ratio, and verify loop bandwidth and output jitter in the Renesas datasheet. Decoupling and return-path layout should follow the manufacturer reference circuit so switching noise is not injected into the sensitive timing path.

Line-Card Timing Reference

The MK2049-45SI is appropriate for line-card timing when the board receives an 8 kHz communications reference and needs one of 14 selectable synthesized clocks. By locking its internal oscillator to the incoming signal, the dual-PLL device can distribute a system-specific clock while reducing input wander and jitter. This architecture is useful in compact line cards where multiple logic domains must share a traceable timing source. The 3.3 V operating supply matches many communications platforms, and the 20-pin SOIC package can simplify board-level integration. Implementation should begin with the exact target output and ratio, then follow the datasheet's loop-filter, crystal, decoupling, and output-routing guidance. Timing margin should be checked across voltage and temperature because detailed limits were not included in the supplied source extract.

Jitter-Attenuated Interface Clocking

The MK2049-45SI can provide jitter attenuation for interface clocking when a higher-frequency reference enters the device and a qualified output is required. Its VCXO-based first PLL uses a pullable crystal to track signal wander, while the buffer selections offer additional ways to configure the clock path. This makes the device relevant to communications and test systems where accumulated phase noise from an upstream source could affect timing margins. The verified 51.84 MHz maximum output rating provides a concrete boundary for initial design selection, but engineers must determine whether the desired output is generated or merely buffered. Component selection should also include the specified pullable crystal, correct loop-filter values, and low-noise layout practices verified from the manufacturer reference design.

Instrumentation Clock Distribution

The MK2049-45SI can be considered for instrumentation clock distribution when a laboratory or industrial instrument needs selectable clocks derived from an 8 kHz reference or a buffered high-frequency source. Its dual-PLL architecture allows one IC to combine synthesis and jitter attenuation, reducing the number of separate clock-conditioning stages when those functions match the family's supported modes. The 3.3 V supply is suitable for many mixed-signal and digital instrument boards, while the 20-pin SOIC package supports conventional surface-mount assembly. Because this is a specialized communications clock PLL rather than a general-purpose function generator, the designer must confirm that the desired frequencies, ratios, and jitter targets appear in the output-selection table. Loop stability and measurement-ground separation are especially important in precision instrumentation.

Industrial Synchronization Network

The MK2049-45SI fits industrial synchronization equipment that distributes a common reference clock among multiple subsystems. Locking to an 8 kHz communications input can establish a repeatable system timing source, while the 14 selectable output frequencies allow local logic to use an appropriate derived clock. The 3.3 V device may be especially relevant to compact control, networking, and embedded communication modules where a separate precision oscillator and synthesis chain would add complexity. The 20-pin SOIC footprint supports assembly and inspection, but the broad operating-temperature and lifecycle details must be obtained from official Renesas documentation before industrial deployment. Layout should keep the PLL loop components and crystal connections compact and mechanically stable, and power filtering must preserve the timing integrity that the jitter-attenuation architecture is intended to provide.