SI5394A-A-GM - 4-Output Jitter Attenuator, 69fs | Skyworks
料号： SI5394A-A-GM ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $57.05 | $57.05 |
| 10 | $51.34 | $513.40 |
| 100 | $45.64 | $4,564.00 |
| 500 | $38.21 | $19,105.00 |
| 1,000 | $33.49 | $33,490.00 |
SI5394A-A-GM 概述
A jitter attenuator is a clock-tree building block placed between a noisy reference oscillator (or recovered clock) and a downstream high-speed transceiver, ADC, or serializer/deserializer (SerDes). The Si5394 integrates a digital PLL (DSPLL) with a MultiSynth fractional output divider tree, allowing it to generate non-integer-related output frequencies from almost any input reference while aggressively attenuating jitter across a wide loop bandwidth. As a member of the clock & timing hierarchy, it sits above simple crystal oscillators and below the system-level timebase, providing a programmable timing layer.
The headline performance numbers are 69 fs RMS phase jitter (12 kHz-20 MHz integration band), 12.8 GHz maximum output frequency, and 12-channel/4-output flexibility. The device also supports free-run, synchronous, and holdover operating modes plus enhanced hitless switching between input references, minimizing phase transients during reference changes. Programming is done through a serial interface with in-circuit programmable non-volatile memory (NVM) so the device always powers up with a known frequency plan.
The Si5394A-A-GM is targeted at 56G PAM4 SerDes, OTN/optical transport, high-speed data-conversion reference clocks, broadcast video, and military/aerospace timing systems. The combination of sub-100 fs jitter and high output frequency makes it one of the highest-performance integrated jitter cleaners on the market.
When designing with this part, engineers should follow the ClockBuilder Pro configuration tool from Skyworks/Silicon Labs and respect the PCB layout note that all supply pins require local decoupling, while the exposed pad must be soldered to a continuous ground plane for thermal and electrical integrity. This page synthesizes distributor pricing, same-package cross-references, and practical design notes not found in the manufacturer datasheet.
直接替换替代料： SI5394A-A-GM ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： SI5394A-A-GM （相同外形与封装尺寸） ——差异在于 Number of Outputs, Package, RoHS Status.
快速对比工具——选择替代料号进行并排对比：
SI5394K-A-GM
✅ 直接替换📋 参考替代料（不在目录中）
SI5394A-A-GMR
✅ 直接替换📋 参考替代料（不在目录中）
SI5395A-A-GM
✅ 直接替换📋 参考替代料（不在目录中）
SI5392A-A-GM
✅ 直接替换📋 参考替代料（不在目录中）
SI5345A-D-GM
✅ 直接替换✓ 有现货
$27.5 / 个
查看数据手册 →SI5394A-A-GM 规格参数
| 功能 | Clock Multiplier / Jitter Attenuator |
| 输出数量 | 4 |
| Number of PLLs | 1 |
| Phase Jitter (RMS) | 69 fs (12 kHz to 20 MHz) |
| Maximum Output Frequency | 1.028 GHz (DigiKey listed); family supports 12.8 GHz internal synthesis |
| Number of Inputs | Differential reference inputs |
| Operating Modes | Free-run, Synchronous, Holdover, Hitless switching |
| Programming Interface | Serial (I2C/SPI) with in-circuit programmable NVM |
| Technology | DSPLL (4th gen) + MultiSynth |
| Channel Count | 12-channel any-frequency, any-output |
| 封装 | 44-VFQFN Exposed Pad |
| 安装类型 | Surface Mount |
| RoHS 状态 | Compliant (per distributor listing) |
SI5394A-A-GM 44-vfqfn exposed pad 引脚配置指南
SI5394A-A-GM（44-vfqfn exposed pad 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： SI5394A-A-GM.
请参阅 数据手册 以查看完整引脚配置。
典型应用
SI5394A-A-GM 适用于 6 应用s: 56G PAM4 SerDes Reference Clock, OTN and Optical Transport Equipment, High-Speed ADC and DAC Reference, Broadcast Video and Studio Timing, Military and Aerospace Timing Systems, Server and Datacenter Clock Tree.
56G PAM4 SerDes Reference Clock
The SI5394A-A-GM's 69 fs RMS phase jitter (12 kHz to 20 MHz) and 12.8 GHz maximum internal synthesis make it purpose-built for 56G PAM4 SerDes reference-clock inputs. SerDes receivers demand sub-100 fs reference jitter to keep the eye diagram open at 28-56 GBaud, and the Si5394 hits the jitter budget with margin while providing four independent differential outputs to drive multiple QSFP-DD or OSFP channels on the same line card. Holdover and hitless switching also protect against momentary reference loss on optical modules without resetting the SerDes link.
推荐
OTN and Optical Transport Equipment
Optical Transport Network (OTN) framers and OTU4/OTUCn line cards require a hitless-switching reference clock that survives a primary reference fail-over without dropping the line. The SI5394A-A-GM's free-run, synchronous, holdover, and enhanced hitless-switching modes meet the telecom GR-1244-CORE jitter-acceptance masks. Its four differential outputs cleanly drive a framer, a gearbox, and a separate crosspoint without needing external fanout, simplifying BOM cost on dense line cards deployed in OTN switches and DWDM transport platforms.
推荐
High-Speed ADC and DAC Reference
Wideband ADCs and DACs above 1 GSPS require a phase-clean sample clock to reach their SNR and SFDR datasheet numbers. The SI5394A-A-GM produces four differential LVPECL/LVDS/HCSL outputs at any frequency up to 12.8 GHz internal synthesis, allowing it to drive the analog front-end, the digital datapath clock, and the JESD204B/C SYSREF lane simultaneously from a single jitter-attenuating source. The 69 fs RMS phase jitter lifts the ADC's aperture-jitter floor, enabling higher ENOB on oscilloscope and radar receiver designs.
推荐
Broadcast Video and Studio Timing
SMPTE 2110, UHD-SDI, and broadcast video routers demand a house reference clock with sub-100 fs jitter and a fanout sufficient to drive dozens of frame-synchr視onizers. The SI5394A-A-GM's 4 output channels and arbitrary frequency synthesis cover common video rates (148.5 MHz, 148.5/1.001 MHz, 27 MHz) while its holdover mode keeps downstream equipment alive during reference-change events. For larger routers, multiple SI5394 parts can be cascaded or used in a star with the SI5345A-D-GM as the higher-channel-count fanout companion.
推荐
Military and Aerospace Timing Systems
Avionics, radar, and secure-radio platforms rely on redundant reference clocks that survive a primary reference fail with bounded phase transients. The SI5394A-A-GM's enhanced hitless-switching and holdover modes support reference redundancy required in DO-160 environments, while its extended-temperature variants provide operation across wide ambient ranges. The in-circuit programmable NVM ensures the device always powers up with a known frequency plan, a critical feature for certifiable platforms that cannot tolerate runtime NVM corruption.
推荐
Server and Datacenter Clock Tree
Hyperscale datacenter switches and PCIe Gen5/Gen6 servers need a low-jitter reference clock with multiple differential outputs to drive CPUs, PCIe retimers, and network PHYs. The SI5394A-A-GM's 4 outputs and DSPLL core provide a clean PCIe reference clock while keeping the BOM area small versus discrete crystal-plus-PLL solutions. For server backplanes requiring more clock domains, the SI5345A-D-GM (10 outputs, higher jitter) is a natural high-density companion on the same board.
推荐
推荐产品汇总
工程参考数据： SI5394A-A-GM ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | SI5394K-A-GM | SI5394A-A-GMR | SI5395A-A-GM | SI5392A-A-GM | SI5345A-D-GM |
|---|---|---|---|---|---|---|
| Brand | Skyworks | Skyworks | Skyworks | Skyworks | Skyworks | Skyworks |
| Package | 44-VFQFN Exposed Pad | 44-VFQFN Exposed Pad - same | 44-VFQFN Exposed Pad - same | 44-VFQFN Exposed Pad - same | 44-VFQFN Exposed Pad - same | 44-VFQFN Exposed Pad - same |
| Number of Outputs | 4 | 4 | 4 | 2 (-50%) | 2 (-50%) | 10 (+150%) |
| Phase Jitter (RMS) | 69 fs (12 kHz to 20 MHz) | 69 fs (same) | 69 fs (same) | 69 fs (same) | Similar DSPLL jitter | >150 fs (higher) |
| Hitless Switching | Yes | Yes | Yes | Yes | Yes | Yes |
| Holdover Mode | Yes | Yes | Yes | Yes | Yes | Yes |
| Programming Interface | I2C/SPI + NVM | I2C/SPI + NVM | I2C/SPI + NVM | I2C/SPI + NVM | I2C/SPI + NVM | I2C/SPI + NVM |
| Tier Position | Mid-tier (4 outputs) | Same tier | Same tier | Lower tier | Lower tier | Higher fanout tier |
关键差异点
- Sub-100 fs RMS jitter vs higher-jitter competitors （对比 SI5345A-D-GM)
- 4-output channel count fits mid-density designs （对比 SI5395A-A-GM)
- Same-family K-grade variant available （对比 SI5394A-A-GMR)
设计说明
All supply pins of the SI5394A-A-GM must be individually decoupled with 100 nF X7R ceramic capacitors placed within 1-2 mm of the supply pin, plus a 10 uF bulk tantalum or polymer capacitor on each supply rail. The exposed thermal pad must be soldered to a continuous ground plane with thermal vias on a 0.5-1 mm pitch grid; omitting the ground-plane connection degrades both EMI performance and jitter. Keep all differential output traces length-matched within 1 mm to avoid duty-cycle distortion at the receiver.
Estimated: When routing the four differential outputs, use 100 ohm differential impedance with 8 mil-to-10 mil trace width on standard FR-4 stackups; pair each output with its complementary trace within 5 mil spacing. Place the input reference traces on a different layer than the outputs to minimize reference jitter pickup. For 56G PAM4 use cases, route the output traces on the top layer over a continuous ground plane to suppress mode conversion.
Do not apply power to the SI5394A-A-GM before the ClockBuilder Pro-generated NVM image is loaded, because the device defaults to a safe low-frequency output until the host MCU configures it. Verify that the I2C/SPI pull-up resistors match the bus speed (typically 4.7 kohm for 100 kHz, 2.2 kohm for 400 kHz). Also be aware that downstream SerDes PHYs may need a fixed-frequency reference at power-up; if so, program the device's NVM image with a known good frequency plan before deployment.
合规信息
RoHS compliant per DigiKey and Mouser listings; AEC-Q100 not applicable as this is a general-purpose industrial/telecom timing part
