PI6C557-03LEX - 200MHz PCIe Clock Generator | Diodes
MPN: PI6C557-03LEX ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.27 | $2.27 |
| 10 | $2.27 | $22.70 |
| 100 | $2.27 | $227.00 |
| 500 | $2.27 | $1,135.00 |
| 1,000 | $2.27 | $2,270.00 |
PI6C557-03LEX Overview
A clock generator produces reference and data-rate clocks for digital circuits that require stable timing, phase control, and predictable edge placement. In a PCI Express system, a spread-spectrum clock can reduce electromagnetic-interference peaks by distributing clock energy over a frequency band. The PI6C557-03 family is designed for PCI Express and Ethernet clock requirements, making it suitable for computer, embedded, communications, and industrial equipment where a local reference clock is needed.
The PI6C557-03LEX provides selectable frequency operation and two differential HCSL output pairs according to the manufacturer datasheet. Its HCSL outputs are intended for high-speed signaling, while configurable spread-spectrum operation helps control radiated and conducted EMI. The manufacturer states that the differential outputs use open-source drivers and require external series and shunt resistors; resistor values and placement should therefore follow the applicable PCI Express layout guidance.
The device accepts a 25 MHz crystal input and generates two pairs of differential outputs at 25 MHz, 100 MHz, 125 MHz, or 200 MHz, depending on configuration. This frequency range supports both low-frequency clock distribution and higher-speed PCI Express clocking. The 3.3 V operating supply and 16-TSSOP surface-mount package support compact PCB designs where external clock conditioning and controlled spread-spectrum operation are required.
Typical applications include PCI Express endpoint and motherboard clocking, embedded computer platforms, Ethernet interface equipment, communications infrastructure, and industrial control systems. The device is most appropriate when a system needs configurable clock selection, differential outputs, and spread-spectrum EMI reduction rather than a simple low-frequency oscillator or single-ended clock buffer.
PCB implementation should preserve short, controlled-length clock traces, provide the required external termination network, and place crystal and decoupling components close to the device. Differential pair routing, return paths, resistor placement, and output configuration must be checked against the manufacturer datasheet and the target PCI Express or Ethernet design guidelines. This page combines verified manufacturer and distributor information with application guidance and replacement analysis.
Drop-in alternatives for PI6C557-03LEX — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PI6C557-03LE
✅ Drop-In📋 Reference alternative (not in catalog)
PI6C557-03ALEX
✅ Drop-In📋 Reference alternative (not in catalog)
PI6C557-03B
✅ Drop-In📋 Reference alternative (not in catalog)
PI6C557-03LEX Maximum Ratings & Electrical Characteristics
| Product Type | PCI Express clock generator |
| Input Clock Frequency | 25 MHz crystal input |
| Maximum Output Frequency | 200 MHz |
| Selectable Output Frequencies | 25 MHz, 100 MHz, 125 MHz, and 200 MHz |
| Output Configuration | Two differential HCSL output pairs |
| Supply Voltage | 3.3 V |
| Operating Temperature Range | -40°C to +85°C |
| Package | 16-TSSOP |
| Mounting Type | Surface mount |
| Clocking Technique | Phase-locked-loop technique |
| Spread Spectrum | Configurable spread-spectrum operation |
| Output Driver Type | Open-source differential HCSL driver |
| External Output Resistors | External series resistor and resistor to ground required |
| Application Support | PCI Express and Ethernet requirements |
| Supplier Classification | Clock Generators, PLLs, Frequency Synthesizers |
| Manufacturer Datasheet URL | https://www.diodes.com/datasheet/download/PI6C557-03.pdf |
| RoHS Status | Compliant, as reported by distributor data |
| Distributor Price | $0.6009 starting price reported by LCSC |
| Verification Date | 2026-10-21 |
PI6C557-03LEX 16-tssop Pin Configuration Guide
Pin configuration for PI6C557-03LEX (16-tssop package). This power device features gate, drain, and source terminals. For non-polarized packages, refer to the manufacturer datasheet for exact pin 1 orientation and footprint details. Common applications include power supply design, motor driving, and load switching.
No detailed pinout data available for PI6C557-03LEX.
Refer to the datasheet for full pin configuration.
Typical Applications
PI6C557-03LEX is suitable for 6 applications: PCI Express Motherboard Clocking, Embedded Computer Platforms, Ethernet Interface Equipment, Industrial Control Systems, Communications Infrastructure, Test and Measurement Systems.
PCI Express Motherboard Clocking
The PI6C557-03LEX fits PCI Express motherboard and add-in-card designs that need a controlled reference clock. Its 25 MHz crystal input and selectable outputs up to 200 MHz support the timing requirements of compatible PCI Express interfaces, while spread-spectrum operation can reduce concentrated EMI peaks. The two differential HCSL output pairs provide separate clock signals for system routing, subject to the external series and shunt resistors required by the manufacturer.
Recommended
Embedded Computer Platforms
Embedded computer platforms can use the PI6C557-03LEX when the design needs a local PCI Express or Ethernet clock source rather than relying only on an upstream oscillator. The 3.3 V supply and 16-TSSOP package are compatible with compact surface-mount assemblies, and the selectable 25 MHz, 100 MHz, 125 MHz, and 200 MHz outputs support multiple clocking domains. Spread-spectrum selection should be evaluated against system timing margins and emissions requirements.
Recommended
Ethernet Interface Equipment
PI6C557-03LEX is suitable for Ethernet-related equipment requiring deterministic differential clock generation and configurable frequency selection. The manufacturer identifies the PI6C557-03 family as supporting PCI Express and Ethernet requirements, and the two HCSL output pairs allow clock distribution to compatible interface circuitry. Layout must keep differential traces controlled and place the required external termination components according to the manufacturer’s PCI Express layout guidance.
Recommended
Industrial Control Systems
The PI6C557-03LEX can provide a stable timing reference in industrial systems that combine high-speed communications with control logic. Its -40°C to +85°C reported operating range and 3.3 V supply fit many embedded industrial boards, while spread-spectrum operation may help manage emissions in equipment cabinets containing multiple high-speed interfaces. Designers should verify clock jitter, output levels, and timing margins against the complete interface specifications.
Recommended
Communications Infrastructure
Communications equipment requiring a local differential clock can use the PI6C557-03LEX for PCI Express or Ethernet interface sections. The selectable 25 MHz through 200 MHz frequencies provide flexibility for multiple interface domains, and spread-spectrum operation can reduce narrowband radiated emissions. The clock traces, return path, termination network, and connector or cable interfaces must be designed together so that HCSL signal integrity and EMC performance are validated in the final assembly.
Recommended
Test and Measurement Systems
A PI6C557-03LEX-based clock source can support test and measurement equipment that needs a controlled high-speed reference distributed to compatible modules. The 200 MHz maximum output and differential HCSL architecture provide useful flexibility for interface cards and clock-distribution fixtures. Because the supplied data does not state jitter, output amplitude, or rise/fall-time limits, those parameters must be read from the manufacturer datasheet before setting test-equipment timing margins.
Recommended
Recommended Products Summary
Engineering reference data for PI6C557-03LEX — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PI6C557-03LE | PI6C557-03ALEX | PI6C557-03B |
|---|---|---|---|---|
| Brand | Diodes Incorporated | Diodes Incorporated | Diodes Incorporated | Diodes Incorporated |
| Package | 16-TSSOP | 16-TSSOP | 16-TSSOP | 16-TSSOP |
| Product Type | PCI Express clock generator | PCI Express clock/frequency generator IC | PCI Express clock generator | PCI Express clock generator |
Key Differentiators
- Selectable multi-frequency clock generation (vs PI6C557-03LE)
- Two differential HCSL output pairs (vs PI6C557-03ALEX)
- PCI Express and Ethernet positioning (vs PI6C557-03B)
Design Notes
Route the two differential HCSL output pairs as controlled-impedance traces with continuous return paths. Keep the pairs matched in length and minimize vias, stubs, and unnecessary branching. Place the required external series and shunt resistors close to the relevant output pins, and verify the final resistor values and locations against the manufacturer datasheet and PCI Express layout guidance. Termination is not optional for these open-source outputs.
Place the 25 MHz crystal and its load components close to the clock-generator input pins, while keeping the crystal loop compact and away from high-current switching nodes. Provide local supply decoupling and a solid ground reference around the 16-TSSOP device. Confirm the package pin numbering from the official datasheet before routing because the supplied web results do not include a complete verified pinout.
Use the configurable spread-spectrum function to reduce concentrated clock-spectrum peaks, but validate the setting in the final PCB and enclosure. Spread spectrum changes spectral distribution and may affect timing margins or downstream filtering. Coordinate the clock configuration with cable, connector, shielding, and chassis layout rather than treating spread spectrum as a substitute for controlled impedance and proper return-path design.
Compliance Information
The verified JLCPCB listing reports ROHS for PI6C557-03LEX. REACH, lead-free, halogen-free, and conflict-minerals status were not provided in the verified data and remain unknown.
