Skyworks Solutions Inc. SI5351A-B05570-GT

Overview

SI5351A-B05570-GT from Skyworks Solutions is an I²C-programmable, 8-output CMOS clock generator with integrated VCXO, generating free-running frequencies from 2.5 kHz to 200 MHz per output with 0 ppm synthesis error. It replaces crystals, crystal oscillators, and discrete VCXOs in cost-sensitive embedded timing applications using a single 25 or 27 MHz AT-cut crystal reference.

For engineers reviewing the SI5351A-B05570-GT datasheet, SI5351A-B05570-GT pinout, SI5351A-B05570-GT application, or SI5351A-B05570-GT equivalent, this device supports independent output voltage supplies (1.8/2.5/3.3 V), glitchless frequency changes, programmable rise/fall times, static phase offset, and spread spectrum control - all configurable via standard-mode or fast-mode I²C.

Technical Context

The SI5351A-B05570-GT implements a dual-PLL architecture: PLL A accepts only the internal 25/27 MHz crystal oscillator (no CLKIN or VC support), while PLL B is disabled in Si5351A variants. Frequency synthesis uses high-resolution MultiSynth fractional dividers downstream of PLL A to generate up to eight independent output clocks.

All outputs derive from a single PLL source, enabling precise inter-output phase relationships and static phase offset configuration. The device lacks VCXO tuning capability - confirmed by datasheet Table 5 (VCXO specs labeled "Si5351B Only") and functional block diagrams showing no VC pin connection in Si5351A configurations.

Key Specifications

Pinout & Package

SI5351A-B05570-GT is housed in a 20-pin QFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are validated per Skyworks datasheet Section 10.1 (Si5351A 20-pin QFN).

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5351A-B-GM and Si5351B-B-GM, SI5351A-B05570-GT provides guaranteed factory-programmed operation out-of-box, eliminating boot-time I²C initialization overhead and ensuring deterministic startup timing - critical for systems requiring immediate clock availability after power-on.

Availability

SI5351A-B05570-GT is available at Aetrix Electronics and suitable for audio/video equipment, networking/communication infrastructure, and industrial instrumentation requiring stable component supply and guaranteed factory-programmed timing behavior.

Supply support for SI5351A-B05570-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 semiconductor company specializing in analog and mixed-signal connectivity solutions, with leadership in RF, timing, and power management ICs.

The Si5351 family is designed for cost-sensitive, space-constrained embedded systems needing flexible, multi-output clock generation - specifically targeting crystal and oscillator replacement in consumer, industrial, and communications equipment.

FAQ

What is the factory-programmed configuration of the SI5351A-B05570-GT?

The SI5351A-B05570-GT is preconfigured at Skyworks to deliver eight specific output frequencies optimized for common multi-clock applications. Configuration data is stored in nonvolatile EEPROM and loads automatically at power-up, eliminating the need for external I²C programming during system boot. This ensures deterministic timing behavior from the first clock edge.

Does the SI5351A-B05570-GT support external clock input (CLKIN) or voltage-controlled tuning (VC)?

No. The SI5351A-B05570-GT is based on the Si5351A variant, which supports only the internal 25 or 27 MHz crystal oscillator (XA/XB) as its timing reference. It does not include CLKIN or VC pins, nor does it implement VCXO functionality - those features are exclusive to Si5351B and Si5351C variants per Skyworks datasheet Rev. 1.3.

What package type and pin count does the SI5351A-B05570-GT use?

The SI5351A-B05570-GT uses a 20-pin QFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad, matching the Si5351A 20-pin QFN footprint defined in Skyworks datasheet Section 10.1. This package supports all eight outputs and independent VDDO supply rails.

Can the SI5351A-B05570-GT generate frequencies above 112.5 MHz on multiple outputs simultaneously?

Yes, but only two *unique* frequencies above 112.5 MHz may be generated simultaneously (e.g., 125 MHz and 130 MHz). Multiple outputs may replicate the same high-frequency signal (e.g., four outputs at 125 MHz), but a third distinct frequency >112.5 MHz is prohibited by the MultiSynth architecture as documented in Skyworks datasheet Table 7 note 1.

How does the SI5351A-B05570-GT achieve 0 ppm frequency error?

The SI5351A-B05570-GT achieves 0 ppm synthesis error through exact fractional division of its 25 or 27 MHz crystal reference using high-resolution MultiSynth dividers. Unlike PLL-based synthesizers with integer-N limitations or analog VCXOs subject to drift, this digital method produces mathematically precise output frequencies without rounding or approximation - verified across its full 2.5 kHz–200 MHz range.