SY89468UHY - 2:20 1.5 GHz LVDS Clock Fanout | Microchip
N.º de pieza: SY89468UHY ✓ ActivoSY89468UHY Descripción general
A clock fanout buffer is a clock-management IC that distributes one or more source clocks to multiple destinations while preserving signal amplitude, edge timing, and clock polarity. The SY89468UHY belongs to the hierarchy of clock buffers and drivers, clock distribution ICs, timing-control devices, and broader semiconductor components. Its differential multiplexer allows a system to select between two clock inputs before distributing the selected clock across twenty outputs.
The key features include a 2:1 differential input multiplexer, a 1:20 fanout ratio, LVDS-compatible outputs, and a maximum listed operating frequency of 1.5 GHz. The internal three-pin termination architecture allows small-amplitude differential inputs without an external termination resistor network in the signal path. Fail-Safe Input behavior is designed to prevent metastable output conditions when the selected differential input fails to a DC voltage.
Internally, the part combines a selectable differential input stage, clock distribution circuitry, and twenty low-voltage differential outputs. The output stage is specified for rise and fall times below 270 ps, making it appropriate for high-speed clock-distribution networks. The 2.5 V ±5% supply requirement supports integration into compact, high-speed digital systems while the exposed pad provides a thermal path from the device to the PCB.
Typical uses include telecommunications equipment, industrial control systems, data-conversion equipment, high-speed computing, network timing, and instrumentation. A single SY89468UHY can feed twenty clock destinations when one selected differential source is sufficient, while the multiplexer supports source redundancy or clock switching between two domains. Care is required to preserve LVDS signal integrity through controlled-impedance routing and correctly terminated differential clock networks.
For PCB implementation, place the device close to the clock source, use matched routing for each differential pair, provide a continuous ground reference, and connect the exposed pad to the appropriate ground plane. Verify input amplitude, common-mode voltage, output termination, and downstream rise-time requirements before releasing the layout.
This page combines the device function, verified timing and supply characteristics, sourcing guidance, and practical layout considerations to support clock-tree design. It also distinguishes the verified SY89468UHY ordering code from related manufacturer ordering and comparison candidates, helping engineers determine whether a proposed replacement preserves the required footprint and electrical behavior.
Alternativas directas para SY89468UHY — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
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| Device Type | 2:20 LVDS clock fanout buffer with 2:1 differential input multiplexer |
| Frecuencia de reloj máxima | 1.5 GHz |
| Tensión de alimentación | 2.5 V ±5% |
| Differential Input Multiplexer Ratio | 2:1 |
| Fanout Ratio | 1:20 |
| Número de salidas | 20 |
| Number of Differential Inputs | 2 |
| Output Logic Standard | LVDS-compatible |
| Minimum Input Signal Amplitude | 100 mV (200 mVPP) |
| Input Coupling | AC-coupled or DC-coupled |
| Output Rise/Fall Time | Less than 270 ps |
| Input Termination | Internal three-pin termination architecture |
| Fail-Safe Input | Yes |
| Rango de temperatura de funcionamiento | -40°C to +85°C |
| Encapsulado | 64-pin TQFP with exposed pad |
| Tipo de montaje | Surface mount |
| Product Line | Micrel Precision Edge |
Guía de configuración de pines de SY89468UHY 64-pin tqfp with exposed pad
Configuración de pines para SY89468UHY (encapsulado 64-pin tqfp with exposed pad). La numeración de pines, las funciones y los diagramas de conexión se definen en la hoja de datos del fabricante. Consúltela para conocer el footprint exacto y las directrices de soldadura.
No hay datos detallados de patillaje disponibles para SY89468UHY.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
SY89468UHY es adecuado para 6 aplicacións: Telecommunications Clock Distribution, Industrial Data-Acquisition Systems, Network Interface Clocking, High-Speed Instrumentation, Data-Converter Synchronization, Server and Computing Clock Trees.
Telecommunications Clock Distribution
The SY89468UHY is suitable for telecommunications clock trees that require one selected differential source to feed twenty destinations. Its 2:1 differential multiplexer allows two clock sources to share a common distribution network, while the 1:20 fanout supports line cards, converters, and interface circuits. The 1.5 GHz operating capability and LVDS-compatible outputs below 270 ps edge rates suit high-speed systems, but designers must confirm source jitter, input common-mode limits, receiver thresholds, and channel skew at the intended operating temperature.
Recomendado
Industrial Data-Acquisition Systems
The SY89468UHY can distribute a common sampling or conversion clock across multiple channels in an industrial data-acquisition system. Twenty outputs reduce the number of separate fanout stages required near converters, interface logic, and processing devices. The device accepts differential clocks as small as 100 mV, providing margin for source attenuation, while its AC- and DC-coupling support broadens clock-source compatibility. Practical implementation requires matched differential routing, receiver-specific termination, and validation of deterministic skew across every fanout branch.
Recomendado
Network Interface Clocking
The SY89468UHY fits network interface designs that need local fanout of a high-speed differential clock to multiple serial or parallel interface blocks. The 2:1 input multiplexer supports selectable sources, while the twenty LVDS-compatible outputs provide one-to-many distribution within a controlled logic domain. Its sub-270 ps guaranteed output edge rate preserves fast transition timing, but usable bandwidth still depends on input amplitude, loss through controlled-impedance traces, downstream receiver thresholds, and the jitter budget of the complete clock path.
Recomendado
High-Speed Instrumentation
The SY89468UHY is useful in high-speed instrumentation where a sampling clock must reach several converters, comparators, or timing blocks. Twenty outputs provide substantial fanout without requiring a cascade of smaller buffers, and the internal input termination architecture accommodates low-amplitude differential sources. Small-signal operation supports source flexibility but demands careful attention to common-mode voltage, connector or trace loss, and return-path continuity. Measure eye height, edge rate, and channel-to-channel skew at each receiver rather than relying only on nominal fanout specifications.
Recomendado
Data-Converter Synchronization
The SY89468UHY can supply a common conversion or sampling clock to multiple data-converter channels in a synchronized measurement system. The differential input multiplexer allows the board to choose between two clock domains, and the twenty outputs reduce the need to duplicate source drive paths. Because converter timing performance depends on edge rate, jitter, and skew rather than frequency alone, validate the clock source against each converter's acquisition requirements. Maintain short matched routes and a continuous ground reference to minimize edge distortion and coupling.
Recomendado
Server and Computing Clock Trees
The SY89468UHY can distribute a selected low-jitter differential clock among multiple logic domains within a server, accelerator, or computing subsystem. Twenty outputs provide broad fanout for local serializers, interfaces, and clock-consuming blocks, while the Fail-Safe Input function helps manage a failed selected source. The device operates from 2.5 V ±5% and supports clocks up to 1.5 GHz, making it appropriate for high-speed logic, but power integrity and thermal design remain essential. Place decoupling near the supply pins and connect the exposed pad to a low-impedance thermal ground structure.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para SY89468UHY — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto |
|---|---|
| Brand | Microchip Technology |
| Package | 64-pin TQFP with exposed pad |
| Device Function | 2:20 LVDS fanout buffer with 2:1 differential input multiplexer |
| Maximum Clock Frequency | 1.5 GHz |
| Supply Voltage | 2.5 V ±5% |
| Number of Outputs | 20 |
| Output Standard | LVDS-compatible |
| Output Rise/Fall Time | Less than 270 ps |
| Minimum Differential Input Amplitude | 100 mV (200 mVPP) |
| Operating Temperature Range | -40°C to +85°C |
Diferenciadores clave
- Combines input multiplexing with twenty-way fanout (frente a SY89825UHY)
- Accepts low-amplitude differential clock signals (frente a SY89467UHY)
- Guarantees very fast LVDS output transitions (frente a SY89825UHY)
Notas de diseño
Route every differential clock pair as a tightly coupled, impedance-controlled pair over a continuous reference plane. Keep the SY89468UHY close to the clock source and place the input, output, and ground-return structures to minimize loop area. Avoid stubs, abrupt width changes, and splits beneath a differential pair because these discontinuities can degrade the sub-270 ps output edge rate even when the nominal operating frequency is acceptable.
Place the required 2.5 V supply and bypass capacitors close to the device's power and ground connections, following the Microchip SY89468U datasheet layout guidance. Keep high-current return paths out of the sensitive clock-routing region, and verify the supply at the pins rather than only at the regulator output. The exposed pad must be connected to the specified thermal and electrical ground structure, with thermal vias placed where they will not disrupt signal routing.
Validate source amplitude, common-mode voltage, receiver thresholds, termination, channel length, and jitter before treating the 1.5 GHz headline frequency as usable system bandwidth. The SY89468UHY accepts signals as small as 100 mV, or 200 mVPP, but small differential inputs require a clean return path and controlled impedance. Measure output eye quality and channel-to-channel skew at the receivers, especially when long cables or connector transitions are present.
Do not treat a related ordering suffix or a nearby family member as an automatic drop-in replacement. SY89468UHY-TR is an ordering form of the same device, while SY89825UHY uses LVPECL outputs and SY89467UHY belongs to a related family. Confirm output voltage standard, pin function, input architecture, fanout ratio, package, and timing behavior before approving any substitute for an existing SY89468UHY layout.
Información de cumplimiento
The manufacturer documentation confirms the -40°C to +85°C industrial temperature range and the Precision Edge product classification. Specific RoHS, REACH, AEC-Q100, lead-free, halogen-free, and conflict-minerals declarations require confirmation from the current manufacturer product documentation.
