Skyworks Solutions Inc. SI5351C-B06543-GM

Overview

SI5351C-B06543-GM from Skyworks Solutions is an I²C-programmable 4-output CMOS clock generator with external reference (CLKIN) synchronization capability, 2.5 kHz–200 MHz output frequency range, <70 ps pk-pk period jitter, and independent 1.8/2.5/3.3 V output supply rails. It replaces crystals, crystal oscillators, and VCXOs in residential gateways and networking equipment.

For engineers reviewing the SI5351C-B06543-GM datasheet, SI5351C-B06543-GM pinout, SI5351C-B06543-GM application, or SI5351C-B06543-GM equivalent, key selection criteria include CLKIN-synchronized multi-domain clock synthesis, VCXO-free operation, per-output spread spectrum control, and 16-QFN (3×3 mm) package compatibility with space-constrained PCB layouts.

Technical Context

The SI5351C-B06543-GM implements a dual-PLL architecture where PLLA and PLLB accept either a 25/27 MHz crystal or an external 10–100 MHz CLKIN reference. Its eight MultiSynth fractional dividers enable independent frequency synthesis per output with 0 ppm error.

It supports static phase offset, programmable rise/fall time, glitchless frequency changes, and configurable spread spectrum (±0.1% to ±1.5% deviation at 31.5 kHz modulation rate). Output buffers are powered by separate VDDO pins for level translation across 1.8 V, 2.5 V, or 3.3 V logic domains.

Key Specifications

Pinout & Package

SI5351C-B06543-GM is housed in a 16-pin QFN (3×3 mm) package with exposed thermal pad. Pin functions align with the Si5351C 16-pin QFN variant per Skyworks datasheet Section 10.6.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5351B-B-GM1, SI5351C-B06543-GM removes VCXO dependency and adds CLKIN flexibility-ideal for reference-synchronized systems. Versus Si5350C-B-GM1, it delivers true fractional synthesis enabling exact non-harmonic frequencies critical for mixed-standard AV and networking gear.

Availability

SI5351C-B06543-GM is available at Aetrix Electronics and suitable for residential gateways, networking equipment, laser range finders, and audio/video equipment requiring stable component supply and long-term design-in support.

Supply support for SI5351C-B06543-GM 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

Skyworks Solutions is a global leader in analog and mixed-signal semiconductors, specializing in RF, mobile, infrastructure, and timing solutions.

The Si5351 family was designed to replace discrete timing components-including crystals, oscillators, VCXOs, and PLLs-in cost-sensitive, space-constrained applications requiring flexible, software-configurable clock generation.

FAQ

What reference inputs does the SI5351C-B06543-GM support?

The SI5351C-B06543-GM supports either a 25 MHz or 27 MHz fundamental-mode AT-cut crystal connected to XA/XB pins, or an external 10–100 MHz clock applied to the CLKIN pin. Unlike the Si5351B variant, it does not require or accept a VC tuning voltage-making it ideal for systems with a stable master reference clock. The SI5351C-B06543-GM uses this reference to lock its dual PLLs and generate up to four independent output frequencies.

How many outputs does the SI5351C-B06543-GM provide, and what are their electrical characteristics?

The SI5351C-B06543-GM provides four CMOS clock outputs (CLK0–CLK3), each configurable from 2.5 kHz to 200 MHz with 0 ppm error. Outputs are grouped into two banks: CLK0/CLK1 powered by VDDOA and CLK2/CLK3 by VDDOB-each bank supports independent 1.8 V, 2.5 V, or 3.3 V supply voltages. Typical period jitter is <70 ps pk-pk, and rise/fall times are 1–1.5 ns (20–80%, CL = 5 pF).

Can the SI5351C-B06543-GM generate non-integer-related frequencies on all outputs simultaneously?

Yes, the SI5351C-B06543-GM uses high-resolution MultiSynth fractional dividers to synthesize any frequency from 2.5 kHz to 200 MHz on each output with zero ppm error-enabling truly independent, non-harmonically related clocks. However, only two unique frequencies above 112.5 MHz may be generated simultaneously (e.g., 125 MHz and 133 MHz), though duplicates of those frequencies are permitted across multiple outputs.

Does the SI5351C-B06543-GM support spread spectrum clocking, and how is it configured?

Yes, the SI5351C-B06543-GM supports per-output spread spectrum clocking with selectable down-spread (–0.1% to –2.5%) or center-spread (±0.1% to ±1.5%) modulation at a fixed 31.5 kHz rate. Configuration is done via I²C register writes-each output's SSC enable bit, deviation step size, and modulation type are individually programmable. This reduces electromagnetic interference without affecting system timing margins.

What package type and thermal characteristics apply to the SI5351C-B06543-GM?

The SI5351C-B06543-GM uses a 16-pin QFN package (3 mm × 3 mm, 0.5 mm pitch) with exposed thermal pad. On a 4-layer PCB, its junction-to-ambient thermal resistance (θJA) is 65 °C/W, and junction-to-board (ΨJB) is 31 °C/W. These values ensure reliable operation up to +85 °C ambient when properly soldered to a thermally enhanced pad-critical for dense residential gateway and networking modules.