SY89467UHY - 1:20 LVPECL Clock Fanout | Microchip
부품 번호: SY89467UHY ✓ 활성SY89467UHY 개요
A clock fanout buffer is a clock-and-timing integrated circuit that reproduces a high-speed differential clock with low skew and controlled impedance. This device combines that distribution function with a 2:1 input multiplexer. The resulting topology is useful when a serializer, transceiver, retimer, FPGA, or communication engine must switch between two clock domains while maintaining a consistent LVPECL interface. Within the product hierarchy, it is a clock buffer and clock multiplexer, both belonging to clock-and-timing ICs and ultimately to the broader semiconductor category.
The SY89467UHY provides 2:1 differential input selection, a 1:20 output fanout ratio, and operation from a 2.5 V or 3.3 V supply. Its listed operating-temperature range is -40°C to +85°C, while distributor records identify the device as a 2 GHz, 64-TQFP exposed-pad clock fanout buffer with multiplexer functionality. These characteristics make the part relevant to high-speed digital systems requiring more output copies than a simple one-to-one clock buffer can supply.
A particularly important feature is Fail-Safe Input protection. According to the Microchip Technology product page, the FSI function helps prevent metastable output conditions when the selected input clock fails to a DC voltage. This behavior supports dependable system operation during clock-source faults, although designers still need to evaluate startup, input biasing, and source-switching requirements against the complete manufacturer application guidance.
Typical uses include high-speed serial links, parallel data converters, telecommunications equipment, test-and-measurement instrumentation, FPGA clock distribution, and data-converter clocking. The 20-output architecture can feed several parallel LVPECL destinations from one selected differential source, while the multiplexer permits redundancy or source selection without requiring two complete downstream clock trees.
The main design consideration is that the exposed-pad package requires careful PCB layout for thermal and electrical performance. Place the device close to the clock source and destinations, keep high-speed traces short and impedance controlled, provide the required decoupling and termination, and connect the exposed pad to the recommended ground-plane construction. Confirm all pin assignments, LVPECL interface details, and unused-output termination against the manufacturer datasheet before fabrication.
This product record combines the manufacturer's functional description with distributor electrical and package details, drop-in replacement information, a parameter comparison, and practical clock-distribution design guidance. It is intended to help engineers identify the correct voltage, package, fanout, multiplexer, and fault-tolerance requirements before integrating the SY89467UHY into a high-speed clock architecture.
드롭인 대체품: SY89467UHY — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
SY89467UHY-TR
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SY89467UHY 사양
| Product Type | LVPECL clock fanout buffer with 2:1 differential input multiplexer |
| Input Configuration | 2 differential inputs |
| 출력 구성 | 20 LVPECL outputs |
| Fanout Ratio | 1:20 |
| Multiplexer Ratio | 2:1 |
| 최대 클록 주파수 | 2 GHz |
| Nominal Supply Voltage | 2.5 V or 3.3 V |
| Operating Supply Voltage Range | 2.375 V to 3.6 V |
| 동작 온도 범위 | -40°C to +85°C |
| 패키지 | 64-TQFP exposed pad |
| 핀 수 | 64 pins |
| 실장 유형 | Surface mount |
| Logic Family | LVPECL |
| Fail-Safe Input | Yes |
SY89467UHY 64-tqfp exposed pad 핀 구성 가이드
SY89467UHY(64-tqfp exposed pad 패키지)의 핀 구성입니다. 핀 번호, 기능, 연결 다이어그램은 제조사 데이터시트에 정의되어 있습니다. 정확한 풋프린트와 솔더링 지침은 해당 문서를 참조하십시오.
다음에 대한 상세 핀아웃 데이터 없음: SY89467UHY.
다음을 참조하십시오: 데이터시트 전체 핀 구성은 다음을 참조하십시오.
일반적인 애플리케이션
SY89467UHY 적합 용도: 6 애플리케이션s: High-Speed Serial-Link Clock Distribution, FPGA Clock Distribution, Data-Converter and Parallel Interface Clocking, Telecommunications Backplane Clocking, Test and Measurement Instrumentation, Clock Redundancy and Source Switching.
High-Speed Serial-Link Clock Distribution
The SY89467UHY fits serial-link clock distribution when the system must select between two differential clock sources and drive multiple LVPECL endpoints. Its 2:1 input multiplexer avoids duplicating the downstream fanout network, while the 1:20 ratio provides 20 outputs for transceivers, retimers, serializers, or interface controllers. Operation up to 2 GHz supports demanding clock trees, and the 2.375 V to 3.6 V supply range accommodates nominal 2.5 V or 3.3 V systems. The design must preserve controlled-impedance routing, apply the manufacturer's LVPECL interface network, and implement the exposed-pad ground and via arrangement. Fail-Safe Input adds value when a selected source can fail to a DC voltage, but downstream logic should still monitor clock health and initiate recovery.
추천
FPGA Clock Distribution
The SY89467UHY is useful when an FPGA or multiple FPGA tiles need low-skew LVPECL clock copies from one of two selectable differential sources. Twenty outputs allow one selected clock to serve several fabric or interface clock inputs without constructing a large tree from discrete buffers. The 2 GHz maximum clock frequency accommodates high-speed fabric and transceiver clocking, while Fail-Safe Input helps constrain output behavior if the selected reference settles at a DC level. In implementation, place the buffer near the clock-source and destination region, use the manufacturer's pinout and exposed-pad layout, maintain controlled impedance, and ensure each LVPECL receiver uses the specified termination. External clock monitoring and switching control remain necessary for deterministic fault recovery.
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Data-Converter and Parallel Interface Clocking
The SY89467UHY can supply multiple parallel data converters, interface controllers, or acquisition channels from a selected differential clock. Its 1:20 fanout provides enough copies for grouped clock domains, and the integrated 2:1 multiplexer permits source redundancy or alternating clock selection. The 2.5 V or 3.3 V operating point aligns with many high-speed mixed-signal systems, while the 2 GHz capability supports demanding sampling or transfer rates. Because converter timing depends on low skew and clean transitions, route clock outputs as short controlled-impedance traces, apply the specified LVPECL termination, decouple supply pins near the device, and keep the exposed pad connected to the recommended ground-plane structure. Validate edge quality and channel-to-channel timing in the final board environment.
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Telecommunications Backplane Clocking
The SY89467UHY is appropriate for telecommunications equipment that requires a selected differential reference clock to reach several line-card or backplane interface circuits. Twenty LVPECL outputs reduce the number of separate fanout stages, while the 2:1 mux supports primary and alternate source selection. Its operation to 2 GHz is suitable for high-rate communication paths, and the stated -40°C to +85°C range covers industrial telecom environments. Board-level implementation is critical: preserve differential impedance, minimize clock-route length and branching, use recommended termination values, and provide a solid ground reference to the exposed pad. Fail-Safe Input improves behavior during a failed DC input condition, but a system-level health monitor and safe state machine should still determine which source is enabled.
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Test and Measurement Instrumentation
The SY89467UHY can distribute a selected high-speed reference clock across multiple acquisition, synthesis, or calibration blocks in test-and-measurement equipment. Twenty outputs allow one LVPECL source to feed instrument sections that require coherent timing, and the integrated 2:1 input selection supports switching between an internal and external reference. The 2 GHz maximum frequency supports demanding test clocks, while nominal 2.5 V or 3.3 V operation fits many mixed-signal instrument architectures. Preserve edge quality by using short routes, continuous reference planes, correct LVPECL termination, and the manufacturer's exposed-pad via pattern. If the instrument expects deterministic phase relationships during source changes, evaluate source isolation and loop-locking behavior because the multiplexer changes which clock reaches all 20 outputs.
추천
Clock Redundancy and Source Switching
The SY89467UHY addresses clock redundancy by selecting between two differential inputs and driving the selected clock to 20 LVPECL outputs. This is useful when a system needs to switch between a primary oscillator, an external reference, or another low-jitter source without duplicating the entire distribution network. The Fail-Safe Input feature helps prevent metastable outputs when the selected input fails to a DC voltage, improving the behavior of a fault transition. Engineering validation should still include switch timing, output continuity requirements, receiver tolerance, and system recovery logic. Keep the two input networks symmetric where possible, use controlled-impedance routing, and monitor both sources through separate diagnostic paths so that a failed reference can be identified before it disrupts the distributed clock.
추천
추천 제품 요약
엔지니어링 참조 데이터: SY89467UHY — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | SY89467UHY-TR |
|---|---|---|
| Brand | Microchip Technology | Microchip Technology |
| Package | 64-TQFP exposed pad | 64-TQFP exposed pad |
| Product Function | 1:20 LVPECL fanout buffer with 2:1 differential input multiplexer | 1:20 LVPECL fanout buffer with 2:1 differential input multiplexer |
| Maximum Clock Frequency | 2 GHz | 2 GHz |
| Input Configuration | 2 differential inputs | 2 differential inputs |
| Output Configuration | 20 LVPECL outputs | 20 LVPECL outputs |
| Fail-Safe Input | Yes | Yes |
주요 차별점
- Combines source multiplexing and wide fanout in one clock-and-timing device (vs SY89467UHY-TR)
- Supports fault-constrained clock distribution (vs SY89467UHY-TR)
- Supports multiple clock destinations from one selected source (vs SY89467UHY-TR)
설계 노트
Implement the 64-TQFP exposed pad with the manufacturer's recommended land pattern, pad connection, and via arrangement. Treat the exposed pad as part of the electrical return network rather than adding thermal vias independently of the documented layout. Position input, output, and supply connections to minimize loop area, and preserve the intended LVPECL impedance on every high-speed trace.
Keep clock routes short, avoid unnecessary stubs, and use the exact input and output termination network specified by the manufacturer. Confirm differential pair geometry and single-ended LVPECL impedance against the final PCB stack-up. At the device's 2 GHz maximum frequency, connector launches, vias, and test pads can create reflections that compromise edge quality even when nominal trace length is acceptable.
Do not assume that selecting a failed clock input automatically produces a valid operating clock. Fail-Safe Input helps prevent metastable outputs when the selected source fails to a DC voltage, but system logic must detect the fault, select a healthy source, and confirm recovery. Also verify unused-output termination and control-pin states against the manufacturer pin-description table before releasing the PCB for production.
규정 준수 정보
No explicit environmental, material, or automotive qualification declarations were identified in the cited product and distributor records. Confirm the current declarations with the manufacturer before regulatory or production release.
