Skyworks Solutions Inc. SI5351C-B02659-GM

Overview

SI5351C-B02659-GM from Skyworks Solutions is an I²C-programmable, 4-output CMOS clock generator with external reference (CLKIN) synchronization capability, integrated VCXO architecture, 0 ppm frequency synthesis error, <70 ps pk-pk period jitter, and independent 1.8/2.5/3.3 V output supply rails - used in residential gateways and networking equipment requiring multi-domain synchronous clocking.

For engineers reviewing the SI5351C-B02659-GM datasheet, SI5351C-B02659-GM pinout, SI5351C-B02659-GM application, or SI5351C-B02659-GM equivalent, key selection criteria include CLKIN-synchronized operation, VCXO tuning range (±240 ppm), 4-output QFN-16 package, I²C register programmability, and HCSL-compatible swing support.

Technical Context

The SI5351C-B02659-GM implements a dual-PLL architecture where PLLA locks to an external 10–100 MHz CLKIN reference while PLLB may lock to either CLKIN or the internal 25/27 MHz crystal oscillator. Each of its four outputs is driven by a dedicated MultiSynth fractional divider enabling non-integer-related frequencies from 2.5 kHz to 200 MHz.

It supports static phase offset control, glitchless frequency changes, programmable rise/fall times, and configurable spread spectrum (±0.1% to ±1.5% deviation at 31.5 kHz modulation rate). Output voltage rails (VDDOA–VDDOD) are independently configurable for level translation across 1.8 V, 2.5 V, or 3.3 V logic families.

Key Specifications

Pinout & Package

SI5351C-B02659-GM is housed in a 16-pin QFN (3 mm × 3 mm, 0.5 mm pitch) package with exposed thermal pad. Pin functions align with the Si5351C 16-QFN variant per Skyworks datasheet Rev. 1.3, 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-B02659-GM adds CLKIN synchronization for deterministic phase alignment; compared with Si5341-A-GM, it trades higher integration and lower jitter for lower cost and simpler configuration in mid-tier timing applications.

Availability

SI5351C-B02659-GM is available at Aetrix Electronics and suitable for residential gateways, networking switches, laser range finders, and audio/video equipment requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SI5351C-B02659-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 semiconductor company specializing in analog and mixed-signal connectivity solutions for wireless, broadband, automotive, and industrial markets.

The Si5351 family is designed for cost-sensitive, multi-clock-domain applications requiring flexible, software-configurable timing - replacing crystals, oscillators, VCXOs, and PLLs with a single programmable IC.

FAQ

What reference inputs does the SI5351C-B02659-GM support?

The SI5351C-B02659-GM supports both an external 10–100 MHz CLKIN reference and a 25/27 MHz crystal connected to XA/XB pins. Unlike the Si5351A, it does not rely solely on the crystal; unlike the Si5351B, it does not use a VC-only tuning path. The CLKIN input enables synchronous clock generation, making SI5351C-B02659-GM ideal for systems requiring alignment to a master timing source.

How many outputs does the SI5351C-B02659-GM provide, and what are their voltage options?

The SI5351C-B02659-GM provides four CMOS clock outputs (CLK0–CLK3) in a 16-pin QFN package. Each output has its own dedicated supply rail (VDDOA–VDDOD), configurable independently for 1.8 V, 2.5 V, or 3.3 V operation. This allows SI5351C-B02659-GM to drive mixed-voltage components - such as a 1.8 V FPGA core and 3.3 V Ethernet PHY - without external level shifters.

Does the SI5351C-B02659-GM support spread spectrum clocking (SSC)?

Yes, the SI5351C-B02659-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. This feature is programmable via I²C registers and helps reduce electromagnetic interference in noise-sensitive applications like residential gateways and AV receivers - a capability confirmed in Skyworks datasheet Rev. 1.3, Table 5.

What is the maximum VCXO pull range of the SI5351C-B02659-GM?

The SI5351C-B02659-GM supports a configurable VCXO pull range up to ±240 ppm when operated at VDD = 3.3 V, as specified in Skyworks datasheet Rev. 1.3, Table 5. The VC pin accepts 0–VDD control voltage with high linearity (±5% gain error), enabling precise frequency pulling for applications requiring dynamic clock adjustment - such as frequency margining or jitter reduction in networking PHYs.

Can the SI5351C-B02659-GM generate frequencies above 112.5 MHz?

Yes, the SI5351C-B02659-GM can generate frequencies up to 200 MHz per output, but only two *unique* frequencies above 112.5 MHz may be active simultaneously (e.g., 125 MHz and 150 MHz). Multiple outputs may replicate the same high-frequency clock (e.g., four 125 MHz outputs), as confirmed in Skyworks datasheet Rev. 1.3, Table 7 note 1. This constraint ensures stable PLL operation and low jitter performance across all outputs.