SY89464UMY - 2:10 Clock MUX Fanout | Microchip Technology
MPN： SY89464UMY ✓ 啟用中SY89464UMY 概覽
A clock multiplexer is a timing IC that selects between multiple clock sources and routes the selected signal to downstream circuits. A clock fanout buffer combines that selection function with multiple low-voltage positive ECL outputs. Together, these devices form the clock and timing hierarchy within semiconductor, interface IC, and clock-and-timing component categories. The SY89464UMY is designed for systems that need controlled source switching, distribution, and low-skew clock delivery.
The differential input architecture uses a three-pin internal termination arrangement that accepts AC- or DC-coupled signals as small as 100 mV, or 200 mV peak-to-peak, without external level-shifting or termination networks. Its ten LVPECL outputs are specified at 800 mV into 100-ohm-compatible loads. This combination makes the device useful where a compact, high-speed clock tree must tolerate small-amplitude source signals while producing standard high-speed differential-clock outputs.
The SY89464UMY is identified as a low-jitter 2:1 differential-input multiplexer with 1:10 LVPECL fanout. Its operating frequency reaches 2 GHz, and the 44-VFQFN exposed-pad package provides a high pin count for separate clock outputs and power-management connections. The exposed thermal pad also supports heat transfer from the device when output-current and switching activity are significant.
Typical uses include redundant reference-clock distribution, high-speed telecommunications timing, server and network-clock fanout, FPGA reference-clock systems, and instrumentation requiring selectable clock sources. In a redundant system, the multiplexer can switch between two independent inputs while the fanout section drives multiple destination devices without requiring a separate one-to-many distribution buffer.
Designers should use the pin-description and typical-application tables in the manufacturer datasheet to assign inputs, enables, power rails, and output terminations. Differential routing should be short and symmetrical, and the exposed pad should be connected to the appropriate ground plane with sufficient thermal copper. Decoupling must follow the datasheet recommendations to preserve low-jitter behavior.
This page organizes the SY89464UMY’s clock architecture, electrical characteristics, application fit, confirmed same-package alternative, and PCB considerations into an engineering-focused guide that extends beyond a basic catalog listing.
直接替換替代品，適用於 SY89464UMY — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
SY89464UMG
✅ 直接替換📋 參考替代品（不在目錄中）
SY89464UMY 規格
| Product Type | 2:10 differential clock multiplexer and 1:10 LVPECL fanout buffer |
| 最大時脈頻率 | 2 GHz |
| Input Configuration | 2 differential inputs |
| 輸出配置 | 10 LVPECL outputs |
| Mux Ratio | 2:1 |
| Fanout Ratio | 1:10 |
| Output Logic Level | 800 mV LVPECL |
| Output Load Compatibility | 100 ohm |
| Minimum Differential Input Amplitude | 100 mV, 200 mV peak-to-peak |
| Input Coupling | AC-coupled or DC-coupled |
| Internal Termination Architecture | 3-pin internal termination |
| 上升時間 | Less than 220 ps |
| 下降時間 | Less than 220 ps |
| 封裝 | 44-pin VFQFN with exposed pad |
| Package Surface Mount Classification | Surface-mount VFQFN |
| Operating Temperature Grade | I temperature grade |
| Environmental Designation | Green |
| Standard Shipping Package | Tray |
SY89464UMY tray 腳位配置指南
SY89464UMY（tray 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： SY89464UMY.
請參閱 資料表 以查看完整腳位配置。
典型應用
SY89464UMY 適用於 6 應用s: Redundant Reference-Clock Switching, FPGA Reference-Clock Distribution, Telecommunications Clock Fanout, Network Equipment Clock Trees, High-Speed Instrumentation Clocks, Test-and-Measurement Multi-Channel Distribution.
Redundant Reference-Clock Switching
The SY89464UMY fits redundant reference-clock systems because it combines a 2:1 differential input multiplexer with ten LVPECL fanout outputs. Two independent low-frequency or high-frequency sources can be presented to the selection stage, while the selected clock is distributed to ten destinations. According to the manufacturer datasheet, the device is optimized for redundant source switchover and operates up to 2 GHz. Differential inputs can be AC- or DC-coupled and may be as small as 100 mV, or 200 mV peak-to-peak, due to the three-pin internal termination arrangement. Ten 800 mV outputs reduce the need for a separate one-to-many LVPECL distribution stage.
推薦
FPGA Reference-Clock Distribution
The SY89464UMY is useful for distributing a selected reference clock to multiple FPGA clock inputs. Its 2:1 differential input stage can select between two clock sources, and its 1:10 fanout provides ten 800 mV LVPECL outputs from the selected path. The 2 GHz operating limit supports high-speed digital processing systems, while differential clock routing can reduce susceptibility to common-mode noise. Because LVPECL is intended for short, properly terminated connections, PCB trace length matching and controlled impedance become important. The 44-pin VFQFN exposed-pad package also gives the design access to separate supply and return connections needed for a clean high-speed clock tree.
推薦
Telecommunications Clock Fanout
The SY89464UMY suits telecommunications equipment requiring selectable clock inputs and multiple high-speed outputs. The 2:1 multiplexer permits source redundancy, while the 1:10 LVPECL fanout distributes the selected clock across ten loads. According to the manufacturer datasheet, the device reaches 2 GHz and produces 800 mV outputs with rise and fall times guaranteed below 220 ps, characteristics useful in high-rate line-card and interface clock trees. The differential input termination architecture accepts small-amplitude signals without a level-shifting network, reducing external circuitry and helping maintain a controlled clock path close to the source.
推薦
Network Equipment Clock Trees
The SY89464UMY can form the central fanout element of a network-equipment clock tree where multiple line cards, transceivers, or fabric devices need a common selectable reference. Ten LVPECL outputs allow one selected differential clock to reach several destinations without cascading separate buffer stages. The 2 GHz rating accommodates high-speed digital infrastructure, and the small-signal input capability can simplify coupling from source drivers. The principal engineering constraint is interconnect discipline: LVPECL links require suitable termination and short controlled-impedance routing. A symmetric layout also helps preserve alignment between the paired clock conductors and limit added timing uncertainty.
推薦
High-Speed Instrumentation Clocks
The SY89464UMY fits instrumentation architectures that need to distribute a selected high-speed clock to several acquisition or processing channels. Its ten 800 mV LVPECL outputs can feed compatible timing circuits, converters, or digital engines, while the 2:1 differential input section supports source selection for test-system flexibility. The manufacturer-described low-jitter architecture is particularly relevant when preserving clock-edge quality matters across multiple outputs. Designers should treat each output as a high-speed transmission line, apply the documented termination method, and keep clock routes away from noisy switching nodes. The exposed pad should be tied to the specified plane and thermal copper to stabilize junction temperature.
推薦
Test-and-Measurement Multi-Channel Distribution
The SY89464UMY supports multi-channel test and measurement systems in which one clock must reach many acquisition, trigger, or processing blocks. The 1:10 fanout provides ten 800 mV LVPECL destinations, reducing the fanout burden on a source oscillator or logic device. Its 2:1 input multiplexer adds source choice, allowing the system to select between clocks without changing the downstream distribution network. Rise and fall times below 220 ps provide the device’s stated edge-speed capability, but practical signal integrity still depends on trace geometry, reference planes, and termination. The 44-pin VFQFN package supports dense routing, while its exposed pad requires careful ground-plane connection.
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推薦產品摘要
工程參考資料，適用於 SY89464UMY — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | SY89464UMG |
|---|---|---|
| Package | 44-VFQFN exposed pad | 44-VFQFN exposed pad |
| Brand | Microchip Technology | Microchip Technology |
| Product Type | 2:10 clock multiplexer and 1:10 LVPECL fanout buffer | 2:10 clock multiplexer and 1:10 LVPECL fanout buffer |
主要差異化特點
- Combines redundant-source selection with ten-output fanout (對比SY89464UMG)
- Accepts small differential input amplitudes without external level shifting (對比SY89464UMG)
- Ten 800 mV LVPECL outputs from one selected clock path (對比SY89464UMG)
設計說明
Route the differential inputs and all ten LVPECL outputs as short, symmetric, controlled-impedance connections. According to the manufacturer datasheet, the outputs are 800 mV LVPECL intended for 100-ohm-compatible loading, and rise and fall times are guaranteed below 220 ps. Apply the documented termination method at each receiver, avoid stubs, and match the paired traces to minimize edge distortion and timing uncertainty.
Place input, output, and bypass connections directly at their associated package pins using the manufacturer pin-description and typical-application diagrams. Keep the 44-pin VFQFN exposed pad connected to the designated ground plane and provide uninterrupted thermal copper beneath the package. Dense clock routing should avoid splits in reference planes and maintain consistent via structures on both conductors of a differential pair.
Do not treat the three-pin internal termination arrangement as permission to omit every external input network without consulting the datasheet. The input can be AC- or DC-coupled and may accept signals as small as 100 mV, or 200 mV peak-to-peak, but source amplitude, common-mode voltage, coupling, and switching requirements still determine the correct configuration. Also verify that all 10 destination loads and their terminations fit the device’s output-routing and thermal constraints.
Use the exposed pad as both an electrical return and a thermal path. Estimate package dissipation from the actual clock output load, output toggle rate, supply voltage, and ambient temperature, then compare the resulting junction-temperature estimate with the manufacturer’s limits. High-frequency clock distribution can create meaningful switching activity even when the logic output voltage is only 800 mV, so provide generous ground-plane copper and avoid enclosing the device with components that obstruct heat flow.
合規資訊
The exact MPN is described as an I-temperature-grade, Green 44-VFQFN exposed-pad device. Formal RoHS, REACH, AEC-Q100, lead-free, halogen-free, and conflict-minerals declarations were not established.
