SY89426JC - 622.08MHz SONET Clock Synthesizer | Microchip
MPN: SY89426JC ✗ End of LifeSY89426JC Overview
A clock synthesizer is a timing IC that derives one or more precisely related output frequencies from an external reference clock. Within the hierarchy of clock and timing integrated circuits, it supports communication infrastructure requiring low deterministic jitter, consistent frequency relationships, and multiple logic-compatible outputs. The SY89426JC uses TTL/CMOS-compatible inputs and provides PECL clock outputs.
The device provides a single-chip source for 622.08 MHz and 155.52 MHz clocks. Its 622.08 MHz output is differential PECL, while the 155.52 MHz output is single-ended PECL. It also includes a reference output and supports SONET-compliant jitter performance stated as 0.01 UI in the retrieved technical data.
The SY89426JC is intended for telecommunications equipment operating at SONET OC-12 and OC-3 line rates. The 622.08 MHz and 155.52 MHz outputs support clock generation in line-card, transceiver, and network-interface designs where a local oscillator must provide both high-speed and divided timing signals.
Use controlled-impedance routing for the differential 622.08 MHz output and provide compliant termination and decoupling close to the device. The 28-LCC package is a leaded ceramic package, so thermal performance and assembly compatibility should be checked against the PCB footprint and manufacturing process.
This page consolidates verified distributor specifications, package information, datasheet links, and design-oriented guidance for the SY89426JC clock synthesizer.
Drop-in alternatives for SY89426JC — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
No drop-in alternatives available for this product.
Request AlternativesSY89426JC Specifications
| Product Type | Clock/Frequency Synthesizer IC |
| Maximum Output Frequency | 622.08 MHz |
| Input Frequency Range | 38.88 MHz to 77.76 MHz |
| Reference Input | TTL |
| Output Type | Differential PECL and single-ended PECL |
| 622.08 MHz Output | Differential PECL |
| 155.52 MHz Output | Single-ended PECL |
| Input Compatibility | TTL/CMOS compatible |
| Reference Output | TTL/CMOS compatible reference output |
| Jitter Performance | 0.01 UI |
| Application | SONET OC-12/OC-3 clock synthesis |
| Number of Circuits | 1 |
| PLL | No |
| Package | 28-LCC (J-Lead) |
| Mounting Type | Surface Mount |
SY89426JC 28-lcc (j-lead) Pin Configuration Guide
Pin configuration for SY89426JC (28-lcc (j-lead) package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for SY89426JC.
Refer to the datasheet for full pin configuration.
Typical Applications
SY89426JC is suitable for 6 applications: SONET OC-12 Line-Card Clocking, OC-3 Optical Transport Equipment, High-Speed Transmitter Timing, Telecommunications Backplane Timing, Synchronous Digital Network Test Equipment, Precision Network Timing Reference.
SONET OC-12 Line-Card Clocking
The SY89426JC fits SONET OC-12 line-card clocking because it generates 622.08 MHz and 155.52 MHz clocks in one device. The 622.08 MHz output is differential PECL, which is appropriate for high-speed transmission sections, while the 155.52 MHz output provides a related lower-rate timing signal. The stated 0.01 UI jitter performance supports timing-budget evaluation, although exact jitter conditions must be confirmed in the datasheet. Keep the high-speed differential route short and controlled-impedance, and verify the device’s input and supply requirements against the line-card clock architecture.
Recommended
OC-3 Optical Transport Equipment
The SY89426JC is relevant to OC-3 optical transport equipment because the 155.52 MHz output corresponds to the SONET-related clock identified in the retrieved feature description, while the 622.08 MHz output supports higher-speed timing. The single-ended PECL output can feed a compatible line-card or transceiver clocking stage after level and termination checks. Because the supplied data does not include supply voltage, output amplitude, or pin-level details, the designer should use the manufacturer datasheet to complete interface validation before layout release.
Recommended
High-Speed Transmitter Timing
The SY89426JC can serve as a timing source for transmitter blocks requiring a stable 622.08 MHz differential PECL clock. Its differential output structure is useful where common-mode noise and edge integrity matter, while the related 155.52 MHz output may support lower-rate synchronization. Use controlled-impedance routing, minimize stubs, and place termination close to the receiving device according to the system’s PECL interface definition. The retrieved data does not state supply voltage or package thermal resistance, so those details remain design-release items.
Recommended
Telecommunications Backplane Timing
The SY89426JC is suitable for evaluating timing distribution in telecommunications backplanes that need a fixed SONET-related clock. Its 622.08 MHz output provides a high-rate differential signal, and the 155.52 MHz output offers a related single-ended clock for lower-rate logic. The device should be placed near the clock-consuming circuits when possible, with return-path and reference-clock routing arranged to limit crosstalk. Because the supplied sources do not provide package dimensions, pinout, or supply details, the physical implementation must be based on the manufacturer package drawing.
Recommended
Synchronous Digital Network Test Equipment
The SY89426JC can be considered for laboratory and production test equipment that generates known SONET-related clocks. The combination of 622.08 MHz differential PECL and 155.52 MHz single-ended PECL outputs allows a test fixture to exercise multiple clock domains while maintaining a related frequency relationship. Test-equipment designs should control input amplitude, termination, and measurement bandwidth, and should compare output jitter against the system mask. The retrieved specification states 0.01 UI performance, but the test conditions are unavailable, so the number should not be treated as a complete jitter guarantee.
Recommended
Precision Network Timing Reference
The SY89426JC may be used in network timing subsystems that need a fixed 622.08 MHz or 155.52 MHz reference derived from an external input. The stated input range of 38.88 MHz to 77.76 MHz and the 0.01 UI jitter specification provide a starting point for architecture work. In practice, the reference source, input distribution, output termination, and measurement bandwidth determine whether the timing requirement is met. Validate these details against the manufacturer datasheet and perform end-to-end jitter testing rather than relying only on the headline frequency specification.
Recommended
Recommended Products Summary
Engineering reference data for SY89426JC — comparison, design guidance, and compliance information.
Selection Guide
Key Differentiators
- Dual related clock outputs (vs SY89296UTG)
- SONET-specific frequency generation (vs SY89296UTG)
- Verified package and output format (vs SY89296UTG)
Design Notes
Route the 622.08 MHz differential PECL output as a short, continuous, impedance-controlled pair. Avoid stubs and unnecessary vias, keep the pair away from switching power nodes, and use the system-defined PECL termination and common-mode arrangement. The supplied data does not specify the exact trace impedance, so use the manufacturer interface guidance and receiver requirements.
Place the required bypass capacitors close to the power and ground pins and provide a low-impedance return path. Before release, confirm supply voltage, current consumption, input thresholds, and output termination from the manufacturer datasheet. Do not infer power limits from the 622.08 MHz output frequency; clock generators can have separate core, interface, and reference power requirements.
Keep the 28-LCC footprint and lead-clearance requirements consistent with the manufacturer package drawing. The supplied results identify the device as 28-LCC/J-Lead but do not provide verified pin names or dimensions. Verify pin numbering, package orientation, and assembly tolerances before committing the PCB layout.
Do not substitute SY89296UTG or another clock IC based only on a comparison-page listing. A valid replacement must match package, pinout, reference-input range, output frequencies, PECL levels, timing behavior, and application requirements. The supplied cross-reference results contain no confirmed drop-in equivalent, so a redesign or qualification review may be necessary.
Compliance Information
The supplied verified data does not provide RoHS, REACH, lead-free, halogen-free, or conflict-minerals information. AEC-Q100 is not applicable based on the identified telecommunications clock-synthesizer category.