SY69753LHI - 155Mbps Clock Data Recovery | Microchip
MPN: SY69753LHI ✗ End of LifeSY69753LHI Overview
A clock and data recovery IC, commonly abbreviated CDR, belongs to the clock and timing IC hierarchy within integrated circuits and semiconductor signal-conditioning devices. Its primary function is to recover a usable clock from a serialized data stream while retiming data against that recovered clock. This allows a receiver to maintain alignment between transmitted data and its associated timing information across a high-speed serial link.
The verified product information identifies the SY69753LHI as a complete clock recovery and data retiming device for OC-3/STS-3 applications at 155 Mbps NRZ. It is listed as a 3.3 V, 155 Mbps application-specific clock and timing IC with one output. The exposed-pad TQFP construction provides a thermal and grounding interface on a 7 mm × 7 mm surface-mount package, although detailed pin names, input tolerances, jitter specifications, and AC timing limits are not present in the supplied source data.
The device is intended for systems where a serial transmitter produces NRZ data at OC-3 or STS-3 rates and the receiver needs regenerated timing rather than a free-running local clock. In this role, the recovered clock can establish a timing reference for subsequent deserialization or return-path multiplexing. Because the verified listing classifies the part as a multiplexer IC with one output, system allocation should provide separate serialization and receive-path functions rather than assuming multiple independent recovered outputs.
Typical applications include SONET/SDH terminal equipment, ATM OC-3 line interfaces, Ethernet-oriented 155 Mbps links, telecommunications line cards, and high-speed data transmission systems. The 155 Mbps NRZ operating mode is especially relevant to legacy and installed transport infrastructure where compliant line-card designs already specify this Micrel-family clock recovery function.
A key design consideration is that the source data does not disclose the exact pin mapping, differential input amplitude, reference-clock requirements, loop bandwidth, or jitter-transfer behavior. Engineers should therefore obtain the manufacturer datasheet and verify signal integrity, termination, decoupling, and exposed-pad layout against the complete electrical specification before releasing a PCB or substituting any component.
This page consolidates verified distributor descriptions, package information, sourcing links, application context, and design cautions. It also distinguishes documented facts from unavailable parameters so engineers can identify what must still be confirmed in the manufacturer datasheet before layout or production use.
Drop-in alternatives for SY69753LHI — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
No drop-in alternatives available for this product.
Request AlternativesSY69753LHI Specifications
| Product Type | Clock recovery and data retiming integrated circuit |
| Manufacturer | Microchip Technology |
| Nominal Operating Voltage | 3.3 V |
| Data Rate | 155 Mbps |
| Supported Low-Speed Listing | 125 Mbps |
| Signal Encoding | NRZ |
| Primary Standard | OC-3/STS-3 |
| Application Class | Ethernet, SONET/SDH, and ATM OC-3 |
| Output Count | 1 output |
| Function | Clock recovery and data retiming |
| Package | 32-TQFP-EP, 7 mm × 7 mm |
| Mounting Type | Surface mount |
| Thermal Pad | Exposed pad |
SY69753LHI 32-tqfp-ep, 7 mm × 7 mm Pin Configuration Guide
Pin configuration for SY69753LHI (32-tqfp-ep, 7 mm × 7 mm 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 SY69753LHI.
Refer to the datasheet for full pin configuration.
Typical Applications
SY69753LHI is suitable for 6 applications: SONET and SDH Line Interfaces, ATM OC-3 Transport Equipment, 155 Mbps Ethernet Receive Paths, High-Speed Serial Data Transmission, Telecommunications Line Cards, Clock and Data Recovery Test Equipment.
SONET and SDH Line Interfaces
The SY69753LHI fits 155 Mbps NRZ OC-3/STS-3 transport paths requiring recovered timing and data retiming. Its verified function is specifically associated with clock recovery and data retiming for SONET/SDH systems, while its 3.3 V supply and one-output configuration identify it as a focused line-interface component. In an existing transport design, the recovered clock can establish alignment for downstream receive functions or return-path multiplexing. The final suitability depends on confirming the datasheet’s pin functions, input amplitude, jitter tolerance, and timing margins; those details are not present in the supplied distributor excerpts and must be checked before schematic or layout release.
ATM OC-3 Transport Equipment
The SY69753LHI is directly associated with ATM OC-3 service at 155 Mbps NRZ, making it applicable to legacy and installed ATM line cards that need clock recovery from the incoming data stream. Its verified 32-TQFP-EP package and single-output architecture fit a dedicated timing-recovery section between the physical receive path and higher-level processing. Using the device can reduce dependence on a separate recovered-clock source, but designers must still validate the complete interface timing and jitter behavior. The supplied excerpts do not specify differential thresholds, reference requirements, loop bandwidth, or pinout, so those parameters must be verified from the manufacturer datasheet.
155 Mbps Ethernet Receive Paths
For established 155 Mbps Ethernet-compatible transport designs, the SY69753LHI can supply the clock-recovery and data-retiming function identified in the verified product descriptions. Placing it in the receive path allows serialized NRZ data to be re-associated with recovered timing before subsequent digital processing. The device operates from a nominal 3.3 V rail and offers one output in a 32-TQFP-EP package, providing a defined integration target for compact telecommunications boards. Because the supplied evidence does not state standard compliance, recovered-clock frequency tolerance, jitter performance, or exact pin functions, engineers should not infer Ethernet interoperability without reviewing the full manufacturer datasheet.
High-Speed Serial Data Transmission
The SY69753LHI is appropriate when a 155 Mbps NRZ serial link requires a dedicated integrated circuit for recovering timing and retiming data. The verified OC-3/STS-3 orientation shows that it targets high-speed telecommunications streams rather than general-purpose low-speed clock distribution. Its recovered output can provide a timing reference for a receive chain or multiplexer section, while the exposed-pad package supports heat transfer from the device during operation. Design sign-off should compare the complete receiver’s signal integrity, jitter budget, loss budget, and termination scheme with the manufacturer’s unreported electrical limits.
Telecommunications Line Cards
A telecommunications line card carrying OC-3/STS-3 traffic at 155 Mbps can use the SY69753LHI in the timing-recovery portion of its receive architecture. Its verified 3.3 V operation, single recovered output, and 32-pin 7 mm × 7 mm exposed-pad package suit compact line-card implementations where an older installed equipment design already uses this Micrel-family function. The device should be placed so the recovered clock has a short and controlled distribution path, while data and clock routing require a return-path layout review. Exact trace geometry, decoupling, exposed-pad thermal design, and signal terminations must follow the complete manufacturer datasheet and reference design.
Clock and Data Recovery Test Equipment
The SY69753LHI can be evaluated in communications test equipment that reproduces a 155 Mbps NRZ receive condition and needs recovered timing for downstream measurement or processing. Its verified clock recovery, data retiming, and one-output functions provide a defined starting point for a laboratory timing subsystem. Compared with a free-running reference clock, a recovered clock remains tied to the incoming data stream, which can simplify characterization of receiver behavior. However, the supplied data does not specify input sensitivity, jitter transfer, acquisition range, or output waveform, so test-equipment use requires bench characterization against the manufacturer specification and careful observation of recovery and locking behavior.
Engineering reference data for SY69753LHI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product |
|---|---|
| Manufacturer | Microchip Technology |
| Brand | Microchip Technology |
| Package | 32-TQFP-EP, 7 mm × 7 mm |
| Data Rate | 155 Mbps |
| Signal Encoding | NRZ |
| Nominal Supply Voltage | 3.3 V |
| Output Count | 1 output |
| Primary Application | OC-3/STS-3 clock recovery and data retiming |
Key Differentiators
- Purpose-built OC-3/STS-3 clock recovery function (vs Generic clock recovery IC)
- Integrated data-retiming function (vs Standalone recovered-clock source)
- Established 32-TQFP-EP integration footprint (vs Alternative package implementation)
Design Notes
Do not finalize the SY69753LHI layout until the complete 32-pin assignment and exposed-pad connection are obtained from the manufacturer datasheet. The verified package is a 7 mm × 7 mm 32-TQFP-EP, and the exposed pad is not a substitute for every ground pin. Place the required power and decoupling connections according to the official recommended layout, keep the data and recovered-clock paths short, and preserve the intended return path beneath high-speed signals.
Treat the incoming 155 Mbps NRZ stream as a high-speed differential signal and validate termination, loss, impedance, jitter, and return-path behavior in the complete channel. The supplied records do not provide input sensitivity, differential voltage, recovered-clock jitter, or loop bandwidth. Consequently, no launch amplitude or termination value can be prescribed from this data. Use the manufacturer’s input model and reference layout, then verify acquisition and recovery margins on hardware before production.
Connect the exposed pad to the package’s required ground and thermal construction exactly as specified in the manufacturer land pattern. Because power dissipation, junction-temperature limits, thermal resistance, and maximum ambient temperature are absent from the supplied data, no numerical thermal calculation can be made. Assess the actual 3.3 V current draw on the assembled board and verify that the PCB thermal design controls junction temperature under worst-case line-card loading.
Do not interpret a distributor category, a search snippet, or a general cross-reference-tool result as proof of pin compatibility. The SY69753LHI-TR ordering code is a tape-and-reel packaging option rather than a distinct functional alternative. Before substituting any part, compare the pin table, 155 Mbps NRZ interface, 3.3 V supply, recovered-clock output, timing margins, jitter characteristics, exposed-pad land pattern, and temperature grade against the original manufacturer datasheet.
Compliance Information
No specific RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations were included in the supplied web data. The AEC-Q100 field is unknown because the supplied listing does not identify an automotive-qualified version.
