DSC557-0343FI0 - 100MHz PCIe MEMS Clock Generator | Microchip
MPN: DSC557-0343FI0 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.85 | $4.85 |
| 10 | $4.36 | $43.60 |
| 100 | $3.88 | $388.00 |
| 500 | $3.49 | $1,745.00 |
| 1,000 | $3.1 | $3,100.00 |
DSC557-0343FI0 Overview
What is a MEMS PCIe clock generator? A clock generator is a timing IC that produces one or more reference frequencies used to synchronize downstream logic such as CPU cores, PHYs, switches, and SerDes lanes. A MEMS (Micro-Electro-Mechanical Systems) clock generator replaces the traditional quartz crystal resonator with a silicon mechanical resonator built on standard CMOS processes, eliminating crystal aging, mechanical shock sensitivity, and the long lead times associated with quartz sourcing. In the PCIe ecosystem, a 100 MHz reference clock with stringent jitter and stability is required to drive PCIe PHYs in endpoints, root complexes, switches, and retimers.
Key features include a 100 ppm total frequency stability across temperature, low additive PCIe-compliant jitter, an Output Enable (OE) pin for power sequencing, HCSL or LVDS compatible differential outputs with a 52 % typical duty cycle, and supply voltage tolerance suitable for 3.3 V rails common in server, storage, and embedded designs. The 14-pin QFN package is 77 % smaller than the equivalent 16-pin TSSOP option, simplifying layout in space-constrained boards.
Architecturally, the device combines an on-chip MEMS resonator with a fractional-N PLL and an HCSL/LVDS driver. Because the MEMS resonator is the frequency reference, no external crystal, load capacitors, or load-capacitor calculation are required, which accelerates board bring-up and removes a known source of oscillator start-up failure.
Typical applications include PCIe Gen1/2/3/4 endpoint and root complex reference clocks on server motherboards, NVMe SSD controllers, network switches and routers, FPGA-based PCIe add-in cards, and industrial embedded platforms that need a robust, lead-free, RoHS-compliant 100 MHz PCIe reference without an external crystal.
When designing with this part, place the device close to the PCIe PHY clock input pins, follow PCIe CEM routing guidelines (100 Ω differential, 90 Ω common-mode where required), and decouple VDD with a 0.1 µF ceramic capacitor placed within 2 mm of the supply pin. Note that this part is a generator, not a buffer, so downstream devices share the single 100 MHz output.
This page synthesizes verified distributor pricing, drop-in Microchip alternatives, and practical PCB layout notes that are not duplicated in the manufacturer datasheet, giving procurement and hardware engineers a single consolidated decision point.
Drop-in alternatives for DSC557-0343FI0 — 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:
DSC557-0343FI1
✅ Drop-In📋 Reference alternative (not in catalog)
DSC557-0344FI1T
✅ Drop-In📋 Reference alternative (not in catalog)
DSC557-0344FI0
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
DSC557-0343FI0T
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
Si52144-A01AGM
✅ Drop-In📋 Reference alternative (not in catalog)
9FGL0241AKILF
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DSC557-0343FI0 Specifications
| Product Type | PCIe Clock Generator (MEMS) |
| Output Frequency | 100 MHz |
| Number of Outputs | 1 |
| Frequency Stability (Total) | ±100 ppm |
| Output Format | HCSL / LVDS differential |
| Duty Cycle | 52 % typical |
| Supply Voltage (VDD) | 2.25 V to 3.6 V (3.3 V typical) |
| Operating Temperature | -40 °C to +85 °C |
| Package | 14-QFN (2.5 mm × 3.2 mm) with EP |
| Mounting Type | Surface Mount |
| Output Enable (OE) Pin | Yes (active-high, disables outputs when low) |
| External Crystal Required | No (crystal-less MEMS resonator) |
| PCIe Compliance | Gen1 / Gen2 / Gen3 / Gen4 |
| RoHS Status | Compliant |
DSC557-0343FI0 Pin Configuration
| Pin 1 | NC — Not connected (per datasheet) |
| Pin 2 | NC — Not connected (per datasheet) |
| Pin 3 | OE — Output Enable (active-high; low disables outputs) |
| Pin 4 | GND — Ground |
| Pin 5 | CLK- — Complementary differential clock output |
| Pin 6 | CLK+ — True differential clock output (100 MHz HCSL/LVDS) |
| Pin 7 | VDD — Power supply (2.25 V to 3.6 V, 3.3 V typical) |
| Pin 8 | NC — Not connected (per datasheet) |
| Pin 9 | NC — Not connected (per datasheet) |
| Pin 10 | NC — Not connected (per datasheet) |
| Pin 11 | NC — Not connected (per datasheet) |
| Pin 12 | NC — Not connected (per datasheet) |
| Pin 13 | NC — Not connected (per datasheet) |
| Pin 14 | EP — Exposed pad - thermal and ground connection (must be soldered to GND plane) |
Typical Applications
DSC557-0343FI0 is suitable for 6 applications: PCIe Gen4 Endpoint Reference Clock, Server and Storage Motherboard Clock Distribution, FPGA-Based PCIe Add-in Card, Network Switch and Router Line Card, Industrial Embedded Computing Platform, Test and Measurement Instrumentation Backplane.
PCIe Gen4 Endpoint Reference Clock
The DSC557-0343FI0 supplies the 100 MHz differential reference clock required by a PCIe Gen1/2/3/4 endpoint PHY on add-in cards, NVMe SSDs, or network interface cards. Its ±100 ppm stability and PCIe-compliant jitter ensure the PHY meets the Gen4 16 GT/s eye mask without reference-clock-induced link errors. Place the device within 25 mm of the PHY clock pins, route CLK+/CLK- as a 100 Ω differential pair, and tie OE high for normal operation or low for power-saving disablement.
Recommended
Server and Storage Motherboard Clock Distribution
On server motherboards and storage backplanes, the DSC557-0343FI0 acts as a local 100 MHz PCIe reference for chipset PHYs, BMC chips, and NVMe controller links. Because it is crystal-less and operates from 2.25-3.6 V, it integrates seamlessly into 3.3 V clock trees and removes the BOM risk of crystal sourcing variability. Multiple instances can be placed across the board to isolate clock domains and minimize long stub traces that would otherwise degrade PCIe signal integrity.
Recommended
FPGA-Based PCIe Add-in Card
FPGA add-in cards implementing PCIe endpoints require a precise 100 MHz reference for the integrated hard PCIe IP block. The DSC557-0343FI0's HCSL/LVDS differential output directly drives the FPGA's clock input pair without additional buffering for short PCB routes, while its MEMS-based stability avoids the frequency drift that would otherwise cause PCIe link training failures. The 14-QFN 2.5×3.2 mm footprint fits easily under the FPGA heat spreader keep-out area.
Recommended
Network Switch and Router Line Card
In network switches and routers, each line card typically hosts one or more PCIe links to the switch ASIC, and the DSC557-0343FI0 provides the local 100 MHz reference for these SerDes links. Its industrial -40 °C to +85 °C range supports deployment in NEBS-compliant telecom environments, and the OE pin enables software-controlled clock gating during low-power states. The 2.5×3.2 mm QFN footprint keeps the clock source close to the ASIC to minimize trace length and impedance discontinuities.
Recommended
Industrial Embedded Computing Platform
Industrial PCs, edge gateways, and HMI controllers use the DSC557-0343FI0 to generate a robust PCIe reference for accelerators and storage devices, where quartz crystals would be vulnerable to shock and vibration in factory-floor installations. The MEMS resonator's inherent tolerance to mechanical stress delivers more consistent PCIe link uptime, and the wide 2.25-3.6 V supply tolerance accommodates the loosely regulated rails typical of industrial power systems.
Recommended
Test and Measurement Instrumentation Backplane
ATE chassis and modular instrumentation platforms route PCIe between instrument modules, and the DSC557-0343FI0 provides a per-module 100 MHz reference that is electrically isolated from chassis-wide clock noise. Its low-jitter HCSL output preserves PCIe Gen3/Gen4 link margin even across long backplane connectors, and the exposed-pad QFN efficiently spreads heat in densely populated modules. The OE pin enables per-module power-down during calibration cycles to reduce system noise.
Recommended
Recommended Products Summary
Engineering reference data for DSC557-0343FI0 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | DSC557-0343FI1 | DSC557-0344FI1T | DSC557-0344FI0 | Si52144-A01AGM | 9FGL0241AKILF |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Silicon Labs | Renesas Electronics |
| Package | 14-QFN (2.5x3.2 mm) | 14-QFN (2.5x3.2 mm) - same | 14-QFN (2.5x3.2 mm) - same | 14-QFN (2.5x3.2 mm) - same | 14-QFN (2.5x3.2 mm) - same | 14-QFN (2.5x3.2 mm) - same |
| Output Frequency | 100 MHz | 100 MHz | 100 MHz | 100 MHz | 100 MHz | 100 MHz |
| PCIe Generation | Gen1 / Gen2 / Gen3 / Gen4 | Gen1 / Gen2 / Gen3 / Gen4 | Gen1 / Gen2 / Gen3 / Gen4 | Gen1 / Gen2 / Gen3 / Gen4 | Gen1 / Gen2 / Gen3 / Gen4 | Gen1 / Gen2 / Gen3 / Gen4 |
| Output Format | HCSL / LVDS differential | HCSL / LVDS differential | HCSL / LVDS differential | HCSL / LVDS differential | HCSL differential | HCSL differential |
| Frequency Stability | ±100 ppm | ±100 ppm | ±100 ppm | ±100 ppm | ±100 ppm | ±100 ppm |
| Supply Voltage | 2.25 V to 3.6 V | 2.25 V to 3.6 V | 2.25 V to 3.6 V | 2.25 V to 3.6 V | 2.5 V / 3.3 V | 3.3 V |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
Key Differentiators
- Crystal-less MEMS resonator eliminates external quartz (vs Traditional PCIe crystal oscillator (e.g. discrete 100 MHz HCSL oscillator))
- 77 % smaller PCB footprint than TSSOP alternative (vs DSC557-03 in 16-pin TSSOP variant)
- Pin-compatible cross-brand drop-in options (vs Single-vendor lock-in for PCIe clock generators)
Design Notes
Place the DSC557-0343FI0 within 25 mm of the PCIe PHY clock input pins and route CLK+/CLK- as a tightly coupled 100 Ω differential pair with no more than two vias on the CLK+ trace. Per the Microchip DSC557-03 datasheet, this minimizes reflections and preserves the PCIe Gen4 jitter margin across the reference clock path.
Decouple VDD with a 0.1 µF X7R ceramic capacitor placed within 2 mm of pin 7, plus a bulk 1 µF capacitor nearby to handle transient current when the HCSL output transitions. The exposed pad (pin 14) must be soldered to a continuous ground plane to provide both the ground reference and the primary thermal path.
Do not leave the OE pin floating - tie it high through a 10 kΩ resistor for normal operation or drive it from the host SoC's GPIO for power sequencing. A floating OE pin can cause intermittent output disable, leading to PCIe link training failures that are difficult to diagnose. Also avoid routing CLK+/CLK- near switching regulator inductors or noisy digital buses to prevent coupled jitter.
Compliance Information
RoHS and REACH compliant per Microchip product page. AEC-Q100 is not applicable for this commercial/industrial timing IC; choose an AEC-Q100-qualified timing part if automotive design is required. Halogen-free status was not stated in the verified data.
