Infineon Technologies CY25100SXIFT

Overview

CY25100SXIFT from Cypress Semiconductor is a field-programmable spread spectrum clock generator (SSCG) IC designed for EMI reduction in high-speed digital systems. It synthesizes and modulates clock outputs using an integrated PLL, supports 3–200 MHz SSCLK output, ±0.25% to ±2.5% center spread or –0.5% to –5.0% down spread, and operates at 3.3 V in 8-pin SOIC package. Used in PC motherboards, graphics cards, and embedded controllers where regulatory EMC compliance is critical.

For engineers reviewing the CY25100SXIFT datasheet, CY25100SXIFT pinout, CY25100SXIFT application, or CY25100SXIFT equivalent, this page delivers verified technical context, real-world design meaning of spread spectrum control, crystal load capacitor tuning, modulation frequency stability, and functional trade-offs between REFCLK and SSCLK outputs.

Technical Context

The CY25100SXIFT implements a proprietary PLL architecture with digitally programmable spread spectrum modulation at a fixed 31.5 kHz frequency, enabling deterministic EMI suppression across its full 3–200 MHz SSCLK range. Its dual-output structure provides a non-modulated REFCLK (same frequency/phase as input) and a modulated SSCLK, both buffered and independently controllable via SSON# and PD#/OE pins.

Crystal interface is fully integrated: CXIN/CXOUT pins support programmable load capacitance from 12 pF to 60 pF in 0.5 pF steps, eliminating external load capacitors. Input flexibility includes 8–30 MHz fundamental crystals or 8–166 MHz external reference clocks, with factory or field programming enabling configuration changes without hardware redesign.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (Small Outline Integrated Circuit), 3.9 mm × 4.9 mm body, 1.27 mm pitch, RoHS-compliant, surface-mount.

Key Features

Applications

Equivalent & Alternatives

Cypress CY25100SXIFT has two verified drop-in alternatives with documented functional and parametric differences:

Compared with IDT 8T49N241 and ON Semi NB3N502, CY25100SXIFT uniquely combines field-programmable spread profile selection, integrated crystal drive with tunable load capacitance, and dual independent outputs-making it optimal for mid-volume, EMI-constrained designs requiring post-silicon tuning.

Availability

CY25100SXIFT is available at Aetrix Electronics and suitable for PC motherboard clock distribution, graphics card timing control, and industrial PLC backplane timing requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for CY25100SXIFT 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

Cypress Semiconductor (now part of Infineon Technologies) is a fabless semiconductor company specializing in programmable system-on-chip (PSoC), memory, and timing solutions for industrial, automotive, and consumer applications.

The CY25100 belongs to Cypress's Spread Spectrum Clock Generator product line, engineered specifically to reduce electromagnetic interference in high-speed digital systems without compromising timing performance or requiring board-level redesign.

FAQ

What is the difference between PD# and OE functionality on Pin 4?

Pin 4 is configurable during programming as either PD# (active-low power-down) or OE (active-high output enable). When configured as PD#, asserting low disables the internal crystal oscillator and PLL, reducing supply current to ≤30 µA. When configured as OE, asserting high enables SSCLK and REFCLK outputs; deasserting places them in high-impedance state. The function is fixed per device and cannot be changed in-circuit.

Can CY25100SXIFT operate with a 100 MHz external reference clock?

Yes. The CY25100SXIFT accepts external reference clocks from 8 MHz to 166 MHz on Pin 3 (XIN/CLKIN). At 100 MHz input, it can synthesize SSCLK outputs up to 200 MHz using its internal PLL. Crystal mode is disabled when using external reference; XOUT (Pin 2) must be left floating, and CXIN/CXOUT should be set to minimum 12 pF.

How does programmable crystal load capacitance improve design yield?

The CY25100SXIFT's 12–60 pF programmable CXIN/CXOUT array replaces external load capacitors, eliminating component variation, solder joint defects, and PCB parasitic uncertainty. By matching crystal CL specification directly (e.g., 30 pF for a 16 pF crystal with 2 pF PCB parasitics), it ensures reliable start-up and frequency accuracy across manufacturing lots and temperature ranges.

Is the 31.5 kHz modulation frequency adjustable?

No. The modulation frequency is fixed at 31.5 kHz across all operating conditions and output frequencies. This value is hard-coded in the device's modulation engine and cannot be altered via programming. It was selected to provide optimal EMI reduction below 1 GHz while avoiding audible noise and maintaining compatibility with common clock receiver bandwidths.