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Skyworks Solutions Inc. SI5518D-B15709-GMR
- Part No.:
- SI5518D-B15709-GMR
- Manufacturer:
- Skyworks Solutions Inc.
- Package:
- 72-VFQFN Exposed Pad
- Datasheet:
-
SI5518D-B15709-GMR.pdf
- Description:
- SI5518D-B15709-GMR
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SI5518D-B15709-GMR from Skyworks is a NetSync™ network synchronizer IC designed for IEEE 1588 Precision Time Protocol (PTP) applications in 5G radio units and small cells. It features four DSPLLs, <55 fs RMS jitter, 1 mHz programmable loop bandwidth, and supports 1PPS input/output with ITU-T G.8273.2 (T-TSC, T-BC) and G.8273.4 compliance. It operates in synchronous, free-run, and holdover modes.
For engineers reviewing the SI5518D-B15709-GMR datasheet, SI5518D-B15709-GMR pinout, SI5518D-B15709-GMR application, or SI5518D-B15709-GMR equivalent, key selection criteria include DSPLL count, 1PPS interface capability, ultra-low jitter performance, ITU-T timing standard compliance, and support for AccuTime™ PTP software integration in O-RAN front-haul and boundary clock systems.
Technical Context
The SI5518D-B15709-GMR implements fifth-generation DSPLL architecture with four independent digital phase-locked loops, enabling simultaneous synchronization to multiple reference inputs including 1PPS and frequency-based clocks. Its loop bandwidth is programmable down to 1 mHz, supporting precise wander filtering for SyncE and holdover stability.
It delivers up to 18 LVPECL/LVDS/HCSL/CML/LVCMOS outputs with per-output format and voltage configuration, and integrates IEEE 1588 DCO control (1 ppt/step) via pin or software. The device natively supports CPRI/eCPRI and JESD204B/C timing requirements for wireless infrastructure.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Jitter (RMS) | <55 fs RMS - enables direct use without external jitter attenuator in 5G RU timing chains |
| DSPLL Count | 4 - supports multi-reference redundancy and hitless switching between SyncE, 1PPS, and PTP-derived references |
| Loop Bandwidth | Programmable down to 1 mHz - meets ITU-T G.8273.2 wander filtering requirements for T-TSC/T-BC |
| Output Count | 18 - provides full clock tree coverage for baseband processing, RFICs, and fronthaul interfaces |
| 1PPS Support | Input and output - enables precise phase alignment and time-of-day distribution in O-RAN deployments |
| Standards Compliance | ITU-T G.8273.1 (T-GM), G.8273.2 (T-TSC, T-BC), G.8273.4 (T-BC-P/A, T-TSC-P/A), G.8262 (EEC), G.8262.1 (eEEC) - certifiable for telecom-grade timing |
| AccuTime™ Support | Full - enables FTS/PTS/APTS PTP operation without third-party stack modification |
Pinout & Package
The SI5518D-B15709-GMR is housed in a 72-pin QFN package (10 mm × 10 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are defined per Skyworks' official Si5518 datasheet revision 1.3, with dedicated 1PPS_IN/OUT, REFCLK inputs, VDDO-supply groups, and configurable output enable/control pins.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1PPS_IN / 1PPS_OUT | Time-of-day reference interface | Enables sub-nanosecond phase alignment across distributed radios; supports automatic 1PPS-to-frequency lock |
| REFCLK[0–1] | Frequency reference inputs | Accepts 8 kHz–1.228 GHz inputs; each assigned to separate DSPLL for multi-source resilience |
| CLKOUT[0–17] | Programmable clock outputs | Individually configurable for LVPECL/LVDS/HCSL/CML/LVCMOS; supports JESD204B/C lane clocking |
| VDDO[0–4] | Output supply domains | Five independent 1.8–3.3 V domains allow mixed-signal SoC interfacing without level-shifting |
| SDA/SCL | I²C configuration interface | Used for dynamic DCO adjustment, PLL reconfiguration, and real-time status monitoring per AccuTime™ protocol |
Key Features
| Feature | Design Value |
|---|---|
| Four DSPLL architecture | Enables concurrent synchronization to 1PPS, SyncE, and PTP-derived references with automatic hitless switching |
| 1 mHz programmable loop bandwidth | Meets strict ITU-T G.8273.2 wander filtering specs for telecom boundary clocks and T-TSC applications |
| 18-format-programmable outputs | Eliminates need for external level translators or buffers when driving heterogeneous RFICs, FPGAs, and ADC/DACs |
| Integrated IEEE 1588 DCO (1 ppt/step) | Allows sub-picosecond phase correction via hardware pin or I²C, reducing software servo latency in PTP stacks |
| AccuTime™ software compatibility | Supports full FTS/PTS/APTS modes out-of-box; enables seamless integration with existing PTP implementations |
Applications
| 5G Radio Unit (O-RU) | Small Cell Base Station |
|---|---|
Use Scenario: Timing synchronization between DU and RU over eCPRI fronthaul with sub-microsecond phase alignment. IC Role / Device Role / Timing Role: NetSync™ network synchronizer providing 1PPS distribution, wander-filtered SyncE recovery, and JESD204B/C lane clocking. Use Value: Eliminates external jitter attenuator and discrete 1PPS fanout buffer; reduces BOM count by three components while meeting 3GPP TR 38.813 ±1.5 μs RU-DU phase error. | Use Scenario: Multi-band LTE/NR small cell requiring holdover stability during GPS outage and rapid reacquisition upon signal return. IC Role / Device Role / Timing Role: Boundary clock with four DSPLLs managing GPS 1PPS, SyncE, and internal oscillator references. Use Value: Achieves <100 ns holdover drift over 24 hours (per G.8273.2 T-BC-A spec) using integrated low-noise oscillators and adaptive loop tuning. |
| O-RAN Front-Haul Gateway | Fixed Wireless Access (FWA) CPE |
Use Scenario: Aggregating timing from multiple O-RUs and distributing synchronized clocks to centralized PHY processors. IC Role / Device Role / Timing Role: Master timing hub with 18 outputs, supporting both CPRI and eCPRI fronthaul clocking standards. Use Value: Enables single-chip timing consolidation across 6–8 RU links; eliminates inter-chip skew and simplifies PCB layout with matched-length routing groups. | Use Scenario: Consumer-grade 5G FWA unit requiring cost-effective, AEC-Q200-aligned timing with GPS backup. IC Role / Device Role / Timing Role: Slave clock with dual DSPLLs tracking GNSS 1PPS and SyncE from upstream fiber node. Use Value: Delivers G.8273.2 T-BC-P compliance at consumer price point; supports seamless handover between GNSS and network-derived timing without service interruption. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar network synchronizer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Si5512D-B15708-GMR | 4 DSPLLs, 12 outputs, same jitter (<55 fs RMS) and 1PPS support, but lacks AccuTime™ full FTS mode | Suitable for T-BC-only deployments without grandmaster or assisted partial timing support | Select when full AccuTime™ FTS integration is not required and output count can be reduced by 6 |
| Si5401D-B15710-GMR | 3 DSPLLs, 10 outputs, <60 fs RMS jitter, identical G.8273.x compliance, but no 1PPS output capability | Targeted at core/metro switches where 1PPS distribution is handled externally | Choose for centralized timing hubs where 1PPS fanout is delegated to dedicated buffers |
Compared with SI5518D-B15709-GMR, Si5512D-B15708-GMR offers identical DSPLL count and jitter but fewer outputs and limited AccuTime™ mode support, while Si5401D-B15710-GMR trades one DSPLL and 1PPS output capability for lower power and smaller footprint in non-fronthaul switch applications.
Availability
SI5518D-B15709-GMR is available at Aetrix Electronics and suitable for 5G O-RU, small cell base stations, O-RAN front-haul gateways, and fixed wireless access CPE requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for telecom infrastructure programs.
Supply support for SI5518D-B15709-GMR 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, Inc. is a global semiconductor company specializing in analog and mixed-signal connectivity solutions for wireless, broadband, automotive, and industrial markets.
The SI5518D-B15709-GMR belongs to Skyworks' NetSync™ family of network synchronizers, engineered specifically for IEEE 1588-compliant timing in 5G RAN, O-RAN, and packet-optical infrastructure where ultra-low jitter, multi-reference resilience, and ITU-T standard compliance are mandatory.
FAQ
What timing standards does the SI5518D-B15709-GMR support?
The SI5518D-B15709-GMR supports ITU-T G.8273.1 (T-GM), G.8273.2 (T-TSC, T-BC), G.8273.4 (T-BC-P/A, T-TSC-P/A), G.8262 (EEC Options 1 and 2), and G.8262.1 (eEEC). These certifications validate its use in telecom-grade boundary clocks, grandmasters, and synchronization equipment deployed in carrier networks and O-RAN architectures.
Does the SI5518D-B15709-GMR require an external crystal?
No, the SI5518D-B15709-GMR is a fully integrated network synchronizer IC with on-chip temperature-compensated oscillators. It accepts external 1PPS and frequency references (e.g., SyncE) but does not require an external crystal or TCXO - all timing synthesis and filtering occur internally using its four DSPLLs and MultiSynth engines.
Can the SI5518D-B15709-GMR generate JESD204B/C-compatible clocks?
Yes, the SI5518D-B15709-GMR supports JESD204B/C lane clocking through its 18 programmable outputs. Each output can be configured for LVDS, CML, or HCSL signaling with precise phase alignment and ultra-low jitter (<55 fs RMS), meeting the deterministic latency and skew requirements of JESD204B/C in 5G radio data converters and FPGA interfaces.
How many reference inputs does the SI5518D-B15709-GMR support?
The SI5518D-B15709-GMR supports two dedicated REFCLK inputs (REFCLK0 and REFCLK1) plus a 1PPS input, allowing concurrent connection to SyncE, GPS-derived 1PPS, and backup frequency sources. All three references can be assigned to its four DSPLLs for redundant timing acquisition and automatic hitless switching.
Is AccuTime™ software required to operate the SI5518D-B15709-GMR?
No, AccuTime™ software is optional. The SI5518D-B15709-GMR operates autonomously in synchronous, free-run, and holdover modes using factory-configured parameters. AccuTime™ adds full IEEE 1588 PTP stack integration (FTS/PTS/APTS), but basic timing functionality - including 1PPS locking, DSPLL steering, and output generation - works without it.
SI5518D-B15709-GMR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Skyworks Solutions Inc.
- Series:
- NetSync™
- Package/Case:
- 72-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- -
- Type:
- Clock Jitter Attenuator
- PLL:
- Yes
- Input:
- CMOS
- Output:
- CML, HCSL, LVCMOS, LVDS, LVPECL
- Number of Circuits:
- 1
- Ratio - Input:Output:
- 6:18
- Differential - Input:Output:
- Yes/Yes
- Frequency - Max:
- 650MHz, 3.2GHz
- Divider/Multiplier:
- Yes/No
- Voltage - Supply:
- 1.8V, 3.3V
- Operating Temperature:
- -40°C ~ 95°C (TA)
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 72-QFN (10x10)
SI5518D-B15709-GMR FAQ
1.How can I place an order for SI5518D-B15709-GMR through Aetrix?
Please submit a Request for Quotation (RFQ) for SI5518D-B15709-GMR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SI5518D-B15709-GMR reliable?
The price and inventory of SI5518D-B15709-GMR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI5518D-B15709-GMR is usually 5 days.
3.What payment methods are accepted for SI5518D-B15709-GMR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI5518D-B15709-GMR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI5518D-B15709-GMR?
SI5518D-B15709-GMR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI5518D-B15709-GMR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SI5518D-B15709-GMR?
For technical support, including SI5518D-B15709-GMR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI5518D-B15709-GMR requirements.
6.How does Aetrix verify that SI5518D-B15709-GMR is sourced from the original manufacturer or authorized distributors?
All SI5518D-B15709-GMR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SI5518D-B15709-GMR meets industry standards.
7.What is the process for return or replacement of SI5518D-B15709-GMR?
All SI5518D-B15709-GMR units undergo pre-shipment inspection (PSI). If there is an issue with SI5518D-B15709-GMR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SI5518D-B15709-GMR part is unused and in its original packaging.
Return procedure for SI5518D-B15709-GMR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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