PCIe clock source with integrated PLL
The 557M-01LF is a single-output PCI Express clock source IC from Renesas, integrating a phase-locked loop (PLL) to generate a clean 100 MHz reference from either a clock or crystal input.

Renesas Electronics 557M-01LF PCI Express clock source IC, integrated PLL, 100 MHz max, HCSL/LVDS outputs, 3.135-3.465 V supply, 8-SOIC, tube.
| Parameter | Value |
|---|---|
| Mounting type | Surface Mount |
| Voltage | 3.135V ~ 3.465V |
| Frequency | 100MHz |
| Operating temperature | 0°C ~ 70°C |
| PLL | Yes |
| Input | Clock, Crystal |
| Output | HCSL, LVDS |
| Package | Tube |
| Main purpose | PCI Express (PCIe) |
| Case | 8-SOIC (0.154\", 3.90mm Width) |
| Number of circuits | 1 |
| Ratio - Input:Output | 1:1 |
| Differential - Input:Output | No/Yes |
The 557M-01LF is a single-output PCI Express clock source IC from Renesas, integrating a phase-locked loop (PLL) to generate a clean 100 MHz reference from either a clock or crystal input.
The 557G-05ALF is a related Renesas PCIe clock source, but it offers a 1:4 fan-out buffer (four outputs from one input) versus the 557M-01LF's 1:1 ratio, and supports up to 200 MHz. The 557M-01LF is the simpler single-output option for a point-to-point PCIe reference clock.
Yes — the input stage accepts either a clock signal or a fundamental-mode crystal, giving the designer flexibility to use a local crystal oscillator or a system clock distribution tree.