Microchip Technology DSC557-0344FI1

Overview

DSC557-0344FI1 from Microchip Technology is a dual-output PCIe Gen1/2/3/4 clock generator with integrated silicon MEMS resonator, delivering two 100 MHz HCSL differential clocks, ±100 ppm frequency stability over –40°C to +85°C, and supply voltage range of 2.25V–3.6V. It replaces external 25 MHz crystals in high-reliability networking and storage systems.

For engineers reviewing the DSC557-0344FI1 datasheet, DSC557-0344FI1 pinout, DSC557-0344FI1 application, or DSC557-0344FI1 equivalent, key selection criteria include PCIe Gen4-compliant jitter (≤86 psPP total jitter), 14-pin QFN package footprint, OE-controlled output enable/disable timing (20 ns enable, 5 ns disable), and dual independent power domains (VDD0/VDD1).

Technical Context

The DSC557-0344FI1 implements a PLL-based clock synthesis architecture with MEMS resonator reference, supporting Common Clock Architecture for PCIe Gen1–Gen4 compliance. Its dual HCSL outputs are independently powered (VDD0 for CLK0±, VDD1 for CLK1±) and share a single OE control input.

It delivers 100 MHz fixed-frequency outputs with 48–52% duty cycle, 750 mVPP single-ended swing, and 200–400 ps rise/fall times into 50 Ω loads. Jitter performance meets PCIe Gen4 requirements: ≤0.5 psRMS integrated phase noise (12 kHz–10 MHz) and ≤86 psPP total jitter under Gen1.1 conditions.

Key Specifications

Pinout & Package

Package: 14-pin QFN (2.5 mm × 3.2 mm), ePAD thermal pad (floating), RoHS-compliant, MSL 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PCIe clock generator applications.

Compared with ICS8430I-01T and Si5332A-D06484-GM, the DSC557-0344FI1 offers optimal balance of PCIe Gen4 compliance, crystal-less reliability, and dual-HCSL simplicity - ideal for cost-sensitive, high-volume networking and storage platforms where fixed 100 MHz timing suffices.

Availability

DSC557-0344FI1 is available at Aetrix Electronics and suitable for Ethernet switching, enterprise SSD controller, and industrial router applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for DSC557-0344FI1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and timing solutions, with global manufacturing and quality certifications including ISO 9001 and AEC-Q200.

The DSC557 family is designed specifically for PCIe-compliant clock generation in communications, storage, and networking infrastructure - prioritizing crystal-less reliability, low jitter, and industrial temperature resilience.

FAQ

What output formats does the DSC557-0344FI1 support?

The DSC557-0344FI1 supports HCSL outputs exclusively - both CLK0 and CLK1 are configured as HCSL differential pairs, as indicated by the "44" suffix in the part number. It does not support LVDS or LVCMOS on this variant; those require different suffixes (e.g., "43" for HCSL/LVDS). The HCSL outputs meet PCIe Gen1–Gen4 Common Clock Architecture requirements with 750 mVPP swing and 50 Ω termination.

Does the DSC557-0344FI1 require an external crystal?

No, the DSC557-0344FI1 does not require an external crystal. It integrates a silicon MEMS resonator that replaces the traditional 25 MHz quartz crystal, eliminating associated layout constraints, aging effects, and mechanical failure modes. This integration is confirmed in the device's General Description and Features sections, and contributes to its MIL-STD-883 qualification for shock and vibration immunity.

What is the operating temperature range for the DSC557-0344FI1?

Per the product identification system and Electrical Characteristics table, the DSC557-0344FI1 is rated for the industrial temperature range of –40°C to +85°C, denoted by the "I" in its part number suffix. This range is validated across all electrical parameters including jitter, startup time, and supply current, and applies to both HCSL outputs under full load conditions.

How is power supplied to the two HCSL outputs on the DSC557-0344FI1?

The DSC557-0344FI1 uses two independent power domains: VDD0 (Pin 13) supplies the core logic and CLK0± outputs, while VDD1 (Pin 12) supplies only the CLK1± outputs. This separation allows independent decoupling and noise isolation - each requires a 0.1 µF capacitor close to its respective pin. The dual-supply architecture minimizes crosstalk between outputs and supports flexible power sequencing in complex systems.

What PCIe generations does the DSC557-0344FI1 support?

The DSC557-0344FI1 complies with PCIe Gen1, Gen2, Gen3, and Gen4 Common Clock specifications, as explicitly stated in its Features and General Description. Its jitter performance - including ≤0.5 psRMS integrated phase noise (12 kHz–10 MHz) and ≤86 psPP total jitter - meets or exceeds the most stringent Gen4 requirements defined in the PCI-SIG specification, ensuring reliable link training and stable operation across all four generations.