Skyworks Solutions Inc. SI5351A-B06165-GT

Overview

SI5351A-B06165-GT from Skyworks Solutions is an I²C-programmable, 8-output CMOS clock generator with integrated VCXO, designed to replace crystals, crystal oscillators, and discrete PLLs in cost-sensitive embedded systems. It delivers up to eight independent, non-integer-related frequencies from 2.5 kHz to 200 MHz with 0 ppm synthesis error, operates from a 25 or 27 MHz crystal, and supports 1.8/2.5/3.3 V output voltage levels for mixed-signal timing in networking and audio/video equipment.

For engineers reviewing the SI5351A-B06165-GT datasheet, SI5351A-B06165-GT pinout, SI5351A-B06165-GT application, or SI5351A-B06165-GT equivalent, key selection criteria include its 20-QFN (4×4 mm) package with 20 pins, VCXO tuning range (±240 ppm at 3.3 V), <70 ps pk-pk period jitter, I²C programmability, and support for HCSL-compatible swing and spread spectrum modulation per output.

Technical Context

The SI5351A-B06165-GT implements a dual-PLL architecture: PLL A accepts either the internal 25/27 MHz crystal oscillator or external CLKIN (10–100 MHz), while PLL B functions as a highly linear VCXO with configurable gain (18–150 ppm/V) and ±5% linearity. Each PLL feeds eight independent MultiSynth fractional dividers, enabling exact frequency synthesis without integer constraints.

Its output stage features separate VDDO supply pins (R0–R7) supporting 1.8 V, 2.5 V, or 3.3 V logic levels per bank, programmable rise/fall time control, static phase offset adjustment, and glitchless frequency transitions - all managed via I²C register writes to RAM or factory-programmed configuration.

Key Specifications

Pinout & Package

SI5351A-B06165-GT is housed in a 20-pin QFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments follow the Si5351A 20-pin QFN layout per Skyworks datasheet Rev. 1.3, Section 10.1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI5351B-B-GM, SI5351A-B06165-GT lacks external CLKIN support but offers identical VCXO performance and pin compatibility; compared with Si5341-A-GM, it trades ultra-low jitter and JESD204B features for lower cost and simpler I²C-only configuration in mid-tier timing applications.

Availability

SI5351A-B06165-GT is available at Aetrix Electronics and suitable for networking equipment, audio/video timing systems, and industrial embedded control requiring stable component supply, long-term lifecycle support, and consistent factory-programmed configurations.

Supply support for SI5351A-B06165-GT 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 with broad manufacturing scale and automotive-grade reliability.

The Si5351 family was designed to replace discrete timing components in cost-sensitive, space-constrained applications - delivering programmable multi-output clock generation with VCXO flexibility, low jitter, and minimal external components.

FAQ

What is the factory-programmed configuration of SI5351A-B06165-GT?

The SI5351A-B06165-GT is preconfigured at the factory using ClockBuilder Pro to deliver eight specific output frequencies optimized for common audio/video and networking use cases. Configuration details - including exact frequencies, output voltages, and spread spectrum settings - are stored in on-chip EEPROM and persist across power cycles without host intervention.

Does SI5351A-B06165-GT support external clock input (CLKIN)?

No. SI5351A-B06165-GT is a Si5351A variant and supports only the internal 25/27 MHz crystal oscillator as its frequency reference. It does not include CLKIN functionality - that capability is exclusive to Si5351B and Si5351C variants. The device relies solely on XA/XB crystal connections for timing reference.

What is the maximum output frequency supported by SI5351A-B06165-GT?

SI5351A-B06165-GT supports output frequencies from 2.5 kHz up to 200 MHz per channel. However, only two unique frequencies above 112.5 MHz may be generated simultaneously (e.g., 125 MHz and 130 MHz), though multiple outputs can replicate the same high-frequency signal.

Can SI5351A-B06165-GT generate HCSL-compatible output swings?

Yes. SI5351A-B06165-GT supports HCSL-compatible output swing through programmable drive strength and termination control. When configured with 50 Ω output impedance and appropriate VDDO (e.g., 1.8 V), it meets HCSL voltage thresholds (V_OH ≥ 0.7 V, V_OL ≤ 0.3 V) and edge rate requirements for PCIe Gen1 and other HCSL-referenced interfaces.

How is thermal performance affected by the 20-QFN package of SI5351A-B06165-GT?

In a 4-layer PCB environment, the SI5351A-B06165-GT's 20-QFN package achieves θ_JA = 41 °C/W and Ψ_JB = 16 °C/W, enabling reliable operation up to +85 °C ambient with typical load (≤45 mA total supply current). The exposed thermal pad must be soldered to a dedicated copper pour for optimal heat dissipation.