Infineon Technologies CY2545QC009

Overview

CY2545QC009 from Cypress Semiconductor is a quad-PLL programmable spread spectrum clock generator in 24-pin QFN package, supporting 8–48 MHz crystal or 8–166 MHz reference input, 3–166 MHz output range, I²C configuration, and fractional-N synthesis for zero-PPM error. It delivers eight glitch-free, independently voltage-programmable clock outputs across three banks for EMI-sensitive PC and networking systems.

For engineers reviewing the CY2545QC009 datasheet, CY2545QC009 pinout, CY2545QC009 application, or CY2545QC009 equivalent, key selection criteria include its four independent PLLs with nonvolatile dual-frequency storage, bank-specific VDD_CLK supply options (1.8/2.5/3.0/3.3 V), spread spectrum modulation profiles (Lexmark/Linear), and I²C-based runtime reconfiguration of drive strength and crystal load capacitance.

Technical Context

The CY2545QC009 implements four fully integrated PLLs-two with spread spectrum (PLL3/PLL4) and two without-each configurable via I²C to generate unrelated frequencies from a single 8–48 MHz crystal or external 8–166 MHz reference. Its crossbar switch enables arbitrary routing of six clock sources (XIN/EXCLKIN, CLKIN, PLL1–PLL4) to eight outputs.

It supports dual nonvolatile frequency configurations per PLL, selected via the multifunction CLK3/FS pin, and guarantees glitch-free switching using output dividers. The device uses fractional-N synthesis to achieve exact integer and non-integer output frequencies with zero PPM error, while maintaining low jitter under 1 ps RMS typical.

Key Specifications

Pinout & Package

24-pin QFN (4 mm × 4 mm, 0.5 mm pitch), thermally enhanced with exposed pad; RoHS-compliant, industrial temperature range (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

CY2545QC009 is functionally matched by two industry alternatives with verified pin compatibility and overlapping specification coverage.

Compared with IDT 8T49N241 and Si5341-B-GM, CY2545QC009 provides optimal trade-off of EMI reduction, low power (65 mW), and eight flexible outputs in a compact QFN-making it ideal for cost-sensitive, space-constrained PC and consumer electronics where spread spectrum is essential and jitter below 1 ps RMS suffices.

Availability

CY2545QC009 is available at Aetrix Electronics and suitable for PC motherboard design, networking switch timing, consumer set-top box development, and industrial embedded controller applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for CY2545QC009 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 U.S.-based semiconductor company specializing in programmable system-on-chip (PSoC), memory, and precision timing solutions for industrial, automotive, and computing markets.

CY2545QC009 belongs to Cypress's legacy Spread Spectrum Clock Generator product line, designed specifically for EMI reduction in high-density digital systems using programmable PLLs, I²C configurability, and multi-voltage clock distribution.

FAQ

What is the maximum crystal load capacitance supported by CY2545QC009?

The CY2545QC009 supports crystal load capacitance values from 12 pF to 20 pF, programmable via I²C register settings. This range accommodates standard AT-cut fundamental-mode crystals commonly used in PC and networking applications. The value is stored in nonvolatile memory and persists across power cycles.

Can CLKIN/RST be used simultaneously as both reset and clock input?

No-CLKIN/RST (Pin 21) operates in one mode at a time, configured during I²C initialization. When set as reset, it asserts asynchronous reset on high; when set as clock input, it accepts 2.5/3.0/3.3 V reference signals. Mode selection is locked after power-up unless reprogrammed via I²C.

How many unique spread spectrum profiles can be stored and switched in real time?

The device stores one spread spectrum configuration per enabled PLL (PLL3 and PLL4), with modulation type (center/down), spread percentage, and profile (Lexmark/Linear) all programmable via I²C. Real-time switching requires external control of the SSON pin or I²C write to the SSC control register-no hardware FS pin is dedicated solely to SSC toggle.

Is the exposed thermal pad on the QFN package electrically connected internally?

Yes-the exposed pad (EPAD) is internally connected to GND and must be soldered to a solid ground plane on the PCB for optimal thermal dissipation and EMI performance. Thermal resistance θ_JA is specified at 42°C/W with 1-inch² 2-oz copper pad; omitting EPAD connection degrades jitter and increases junction temperature by >15°C.