MK2745-24SLF - DVD/MPEG Clock Synthesizer | Renesas
부품 번호: MK2745-24SLF ✓ 활성MK2745-24SLF 개요
A clock synthesizer is a clock-and-timing IC that generates or distributes multiple related clock signals from one stable reference. It belongs to the PLL-based clock-generator family, where a phase-locked loop locks output frequencies to the input reference. This hierarchy places the MK2745-24SLF within clock generation, clock and timing ICs, and broader semiconductor-based system timing control. Such consolidation can reduce the number of separate oscillators and clock buffers required in multimedia equipment.
The principal features are support for a 27 MHz crystal or clock source, multiple audio outputs, one processor clock, and two 27 MHz clock outputs. Its analog PLL architecture is designed for low-cost, low-jitter clock generation in consumer-oriented DVD and MPEG-2 systems. The 3 V to 5.5 V operating range permits use with common digital supply rails, although designers should maintain appropriate sequencing, decoupling, and output-load margins for every connected circuit.
The processor clock and dedicated 27 MHz outputs allow a multimedia system to derive several timing domains while maintaining a common phase relationship. The audio outputs serve clock-sensitive decoding and signal-chain sections, while the processor clock supports digital control logic. Because the device consolidates these functions into one synthesizer, board partitioning can be simpler than with multiple unrelated oscillators, provided each output's frequency, drive capability, and enabled state satisfy the load requirements.
Typical applications include DVD players, DVD recorders, MPEG-2 multimedia systems, set-top equipment, digital audio/video appliances, and embedded consumer electronics requiring coordinated audio and processor clocks. The reference design should use the manufacturer's recommended crystal or clock network and pin-compatible input/output loading. Designers should also account for trace capacitance, EMI coupling, and the maximum fan-out of each clock output.
The main design consideration is preserving clock quality through the PCB. Place the crystal and associated load network close to the device, keep clock traces short and impedance-controlled, and provide local bypass capacitance on the supply pins. Avoid routing high-current or switching-node traces beneath the oscillator network, because displacement current and supply ripple can degrade jitter even when the nominal output frequency is correct.
This product record combines the manufacturer's clock-function description with package, interface, and supply information, then adds practical integration guidance, sourcing paths, and strict replacement criteria. It identifies where a same-footprint substitute must be verified rather than treating similarly named clock ICs as automatically interchangeable.
드롭인 대체품: MK2745-24SLF — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 제품에는 사용 가능한 드롭인 대체품이 없습니다.
대체품 요청MK2745-24SLF 사양
| Device Type | Clock synthesizer / DVD-MPEG clock source |
| Architecture | Analog phase-locked loop (PLL) |
| Reference Input | 27 MHz fundamental-mode crystal or clock input |
| Reference Frequency | 27 MHz |
| Supply Voltage Range | 3 V to 5.5 V |
| 인터페이스 유형 | CMOS |
| Audio Clock Outputs | Multiple outputs |
| Processor Clock Output | 1 processor clock output |
| Additional Clock Outputs | 2 outputs at 27 MHz |
| Jitter Characteristic | Low jitter |
| Target Application | DVD and other MPEG-2-based applications |
| Package Type | 16-pin SOIC, 0.150 inch |
| Package Body Width | 0.154 inch (3.90 mm) |
| 실장 유형 | Surface mount |
MK2745-24SLF 0.154 inch (3.90 mm) 핀 구성 가이드
MK2745-24SLF(0.154 inch (3.90 mm) 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: MK2745-24SLF.
다음을 참조하십시오: 데이터시트 전체 핀 구성은 다음을 참조하십시오.
일반적인 애플리케이션
MK2745-24SLF 적합 용도: 6 애플리케이션s: DVD Player Clock Architecture, MPEG-2 Multimedia System, Digital Audio Playback Equipment, Processor Timing Subsystem, Set-Top Multimedia Appliance, Consumer Video Processing Equipment.
DVD Player Clock Architecture
The MK2745-24SLF fits a DVD-player clock architecture because it accepts a 27 MHz crystal or clock reference and generates several related outputs from an analog PLL. The device provides multiple audio clocks, a processor clock, and two 27 MHz clocks, allowing the designer to establish a coordinated timing tree from one reference source. Use it where the system architecture requires these defined clock domains and the 3 V to 5.5 V operating range is compatible with the surrounding electronics. Placement is especially important: keep the oscillator network short, provide local supply bypassing, and route clock outputs away from switching nodes. The benefit is fewer discrete timing components and a common reference relationship, while the tradeoff is that the exact output frequency and loading plan must conform to the manufacturer's application circuit.
추천
MPEG-2 Multimedia System
The MK2745-24SLF is appropriate for MPEG-2-based multimedia equipment requiring coordinated audio, processor, and system clocks. Its 27 MHz reference input and analog PLL provide a unified timing reference, while the multiple audio outputs support clock-dependent decoding and signal-processing sections. The two additional 27 MHz outputs can serve compatible system domains when the manufacturer output plan and load limits permit it. This integration reduces the number of unrelated clock sources that must be coordinated. During design review, verify each output frequency, enable state, drive margin, and destination-device input tolerance. The main implementation benefit is simpler clock distribution; the main limitation is that the circuit is specialized for the defined multimedia timing architecture rather than a universal arbitrary-clock generator.
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Digital Audio Playback Equipment
The MK2745-24SLF can support digital audio playback systems where several synchronized clocks are required around an MPEG-2 or DVD-oriented signal chain. Multiple audio clock outputs allow compatible converters, decoders, and processors to operate from related timing sources rather than independently generated signals. The 27 MHz input also provides a reference for the processor clock and two additional 27 MHz outputs. Designers should examine clock-to-audio timing margins, output jitter requirements, and the exact enable sequence in the manufacturer datasheet. Keep audio-clock traces short and isolated from digital return currents, and bypass the supply locally. This arrangement simplifies the clock architecture, but it does not eliminate the need to validate jitter and interface compatibility with each connected audio device.
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Processor Timing Subsystem
Within a multimedia controller design, the MK2745-24SLF supplies a defined processor clock together with system timing outputs derived from the same 27 MHz reference. This arrangement can make clock relationships easier to manage in equipment where the processor, audio path, and auxiliary logic must start and remain synchronized. The analog PLL architecture is tailored to the device's DVD and MPEG-2 use case, so it should be selected only when its output plan matches the processor interface. Verify processor input-voltage thresholds, maximum clock frequency, allowable jitter, and startup sequencing. Place the reference network close to the device and maintain short clock routes. The benefit is consolidated timing, while the tradeoff is limited configurability compared with a general-purpose programmable clock generator.
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Set-Top Multimedia Appliance
The MK2745-24SLF can support the clock tree of a set-top or MPEG-2 appliance that requires processor timing, audio clocks, and repeated 27 MHz domains. A single reference arrangement simplifies synchronization between functional blocks that would otherwise depend on separate oscillators. The device's 3 V to 5.5 V supply range is compatible with many embedded logic rails, provided sequencing and noise conditions are managed correctly. During layout, isolate the reference and clock paths from video, power-conversion, and high-speed data routing, and use a quiet supply plane or filtered rail where switching ripple could affect jitter. This application benefits from fewer timing components and tighter phase relationships, but only after confirming the manufacturer's output frequencies and fan-out requirements against the appliance architecture.
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Consumer Video Processing Equipment
The MK2745-24SLF is applicable to consumer video-processing equipment built around MPEG-2 or DVD-compatible timing requirements. Its multiple audio outputs, processor clock, and two 27 MHz outputs can provide the clock domains required by a coordinated multimedia pipeline. Using one synthesizer helps establish predictable relationships between the processor and associated audio circuitry, while the analog PLL supports low-jitter clock generation. Engineering validation should include output-load testing, power-up sequencing, supply ripple sensitivity, and PCB-level jitter measurement at each destination. Keep traces short, avoid split or stubbed clock branches unless explicitly allowed, and preserve the manufacturer reference layout around the crystal. The tradeoff is that the fixed output architecture may be less flexible than a programmable clock solution for new product variations.
추천
엔지니어링 참조 데이터: MK2745-24SLF — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 |
|---|---|
| Brand | Renesas Electronics |
| Package | 16-pin SOIC, 0.150 inch |
| Device Type | Clock synthesizer / DVD-MPEG clock source |
| Architecture | Analog phase-locked loop |
| Reference Input | 27 MHz crystal or clock input |
| Supply Voltage Range | 3 V to 5.5 V |
| Audio Clock Outputs | Multiple outputs |
| Processor Clock Output | 1 processor clock output |
| Additional Clock Outputs | 2 outputs at 27 MHz |
주요 차별점
- Integrated multimedia clock set (vs Generic single-output clock oscillators)
- Purpose-built DVD and MPEG-2 clock architecture (vs General-purpose programmable clock generators)
- Common CMOS supply operating range (vs Higher-voltage legacy clock synthesizers)
설계 노트
Place the 27 MHz crystal and the manufacturer-recommended load network immediately adjacent to the reference pins. Keep reference traces short, avoid test pads and branch stubs, and route them away from switching nodes and high-current returns. Because coupled displacement current can increase clock jitter, preserve a continuous reference ground path and compare the final layout with the application circuit in the Renesas MK2745-24 datasheet.
Provide local bypass capacitance at the supply pins and keep the high-current return path close to the device. Verify startup behavior with the actual 3 V to 5.5 V supply ramp and confirm that downstream circuits do not drive clock outputs during power-up. Supply ripple and improper sequencing can affect PLL behavior or clock availability even when the nominal input and output frequencies are correct.
Treat every generated clock as a high-speed signal. Match routing to the output characteristics and load limits in the manufacturer datasheet, minimize capacitive loading, and avoid unnecessary test pads. If a clock must fan out, use short branches or a qualified clock buffer rather than adding an uncontrolled divider. Confirm rise time, duty-cycle distortion, and jitter at each receiver rather than assuming that acceptable behavior at the source guarantees endpoint compliance.
규정 준수 정보
The manufacturer description identifies a DVD/MPEG clock synthesizer, but the supplied technical information does not state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. AEC-Q100 is not applicable because this is a clock-and-timing IC rather than an automotive-qualified device.
