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Infineon Technologies CY2545QC021
- Part No.:
- CY2545QC021
- Manufacturer:
- Infineon Technologies
- Package:
- 24-UFQFN Exposed Pad
- Datasheet:
-
CY2545QC021.pdf
- Description:
- IC FANOUT DIST 24QFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,579
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Product details
Overview
CY2545QC021 from Cypress Semiconductor is a quad-PLL programmable spread spectrum clock generator with I²C interface, designed for precise multi-frequency synthesis in timing-critical systems. It delivers eight programmable clock outputs (3–166 MHz), supports fractional-N synthesis for zero-PPM error, and integrates independent voltage banks (1.8 V/2.5 V/3.0 V/3.3 V) for mixed-voltage system clocking - deployed in PC motherboard BIOS clocks and embedded networking controllers.
For engineers reviewing the CY2545QC021 datasheet, CY2545QC021 pinout, CY2545QC021 application, or CY2545QC021 equivalent, key selection criteria include verified 24-pin QFN package compatibility, confirmed I²C-programmable spread spectrum (center/down, ±0.125% to ±2.5%), glitch-free frequency switching via FS pin, and bank-specific output drive strength configuration.
Technical Context
The device implements four independent PLLs - PLL1 and PLL2 provide standard clock synthesis, while PLL3 and PLL4 integrate proprietary spread spectrum modulation (Lexmark/Linear profiles) for EMI reduction. Each PLL supports fractional-N division enabling exact non-integer frequency generation without rounding error.
Three output banks (Bank1: CLK1–CLK2; Bank2: CLK3–CLK5; Bank3: CLK6–CLK8) are powered by separate VDD_CLK_Bx supplies, allowing simultaneous 1.8 V, 2.5 V, and 3.3 V clock outputs. The crossbar switch enables arbitrary routing of six internal sources (XIN, CLKIN, PLL1–PLL4) to any output, with glitch-free transitions during frequency-select pin (CLK3/FS) toggling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| PLL Count | Four fully integrated, independently programmable PLLs for concurrent unrelated frequency synthesis |
| Output Frequency Range | 3 MHz to 166 MHz - covers PCIe Gen1–Gen3 reference clocks, DDR memory interfaces, and USB 2.0 PHY timing |
| Spread Spectrum | Center-spread ±0.125% to ±2.5% or down-spread –0.25% to –5.0% - configurable per PLL3/PLL4 for certified EMI reduction |
| I²C Interface | Standard two-wire serial interface (SCL/SDA) for nonvolatile register programming and real-time control of PLLs, drive strength, and SSC |
| Input Reference | Crystal (8–48 MHz) or external clock (8–166 MHz) on XIN/EXCLKIN or CLKIN/RST pins - supports dual-reference redundancy |
| Output Banks | Three independent voltage banks (Bank1/Bank2/Bank3) with selectable VDD_CLK_Bx supplies - enables mixed-voltage SoC clock tree integration |
| Package | 24-pin QFN (4 mm × 4 mm, 0.5 mm pitch) - RoHS-compliant, thermally enhanced for high-density PCB layouts |
Pinout & Package
24-pin QFN (4 mm × 4 mm, 0.5 mm pitch), exposed thermal pad, RoHS-compliant. Pin 1 marked by top-side dot; pin numbering follows standard counter-clockwise sequence starting from top-left corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pins 1, 7, 12, 18, 19) | Power ground | Five dedicated ground connections ensure low-noise reference for all PLLs and output drivers |
| VDD (Pin 22) | Core supply input | 2.5 V / 3.0 V / 3.3 V core power - powers internal logic, I²C interface, and PLL charge pumps |
| VDD_CLK_B1 (Pin 3) | Bank1 output supply | Supplies CLK1 and CLK2 outputs - must match or exceed VDD voltage; sets output swing level |
| CLKIN/RST (Pin 21) | Reference input / reset | Configurable as 2.5–3.3 V clock input or active-high reset - requires valid EXCLKIN signal when used as clock source |
| PD#/OE (Pin 4) | Control input | Programmable as active-low power-down or output-enable - disables all outputs without resetting PLL configuration |
| SCL / SDA (Pins 8, 9) | I²C interface | Standard bidirectional I²C bus - supports configuration write/read, real-time SSC enable/disable, and bank voltage monitoring |
| XIN/EXCLKIN (Pin 24) | Crystal/clock input | Accepts 8–48 MHz crystal or 1.8 V/2.5 V/3.3 V external clock - primary reference for PLL lock stability |
| CLK1–CLK8 (Pins 2, 6, 10, 11, 13, 15, 17, 20) | Programmable clock outputs | Eight outputs with independent source selection (PLL1–PLL4, XIN, CLKIN), spread control, and drive strength per bank |
Key Features
| Feature | Design Value |
|---|---|
| Fractional-N PLL synthesis | Enables exact frequency generation (e.g., 100.000000 MHz) with zero PPM error - eliminates timing skew in synchronous interfaces |
| Glitch-free frequency switching | Hardware-controlled transition between two preloaded PLL configurations using CLK3/FS pin - maintains continuous clocking during dynamic CPU/GPU DVFS |
| Independent output voltage banks | Three isolated VDD_CLK_Bx supplies allow simultaneous 1.8 V (I/O), 2.5 V (PCIe), and 3.3 V (legacy peripherals) clock outputs from one IC |
| Nonvolatile configuration memory | Stores PLL dividers, SSC parameters, drive strength, and crystal load capacitance - retains settings across power cycles without external EEPROM |
| EMI-optimized spread spectrum | Dual-profile (Lexmark/Linear) modulation on PLL3/PLL4 - meets FCC Class B radiated emissions limits without added shielding or ferrites |
Applications
| PC Motherboard Clock Tree | Networking Switch ASIC Timing |
|---|---|
Use Scenario: Generating synchronized clocks for CPU, memory controller, PCIe root complex, and SATA PHY on x86-based motherboards. IC Role / Device Role / Timing Role: Primary clock generator providing eight phase-aligned, spread-spectrum-enabled outputs with bank-isolated voltage domains. Use Value: Eliminates need for multiple discrete clock ICs; reduces board space by 60% and EMI filter count by 4× versus fixed-frequency oscillators. | Use Scenario: Supplying jitter-clean reference clocks to multi-port Ethernet switch ASICs requiring 125 MHz (SFP+), 156.25 MHz (10GbE), and 250 MHz (PHY backplane). IC Role / Device Role / Timing Role: High-accuracy, programmable clock source with fractional-N synthesis and <1 ps RMS jitter for deterministic packet forwarding timing. Use Value: Enables single-device support for IEEE 802.3bj/802.3by compliance testing across multiple line rates without hardware change. |
| Industrial PLC Controller | Embedded Media Gateway |
Use Scenario: Providing isolated, EMI-hardened clocks to ARM Cortex-A9 dual-core processor, DDR3 memory, and EtherCAT master interface in factory automation controllers. IC Role / Device Role / Timing Role: Spread spectrum clock generator with industrial temperature range (–40°C to +85°C) and glitch-free frequency switching for real-time task scheduling. Use Value: Reduces radiated emissions by 8 dBμV at 150 MHz - achieves EN 61000-6-4 compliance without enclosure redesign. | Use Scenario: Clocking video decoder (H.264), audio codec (I²S), and Wi-Fi baseband (802.11n) in compact set-top box designs. IC Role / Device Role / Timing Role: Multi-voltage clock hub delivering 27 MHz (video), 12.288 MHz (audio), and 40 MHz (Wi-Fi) from single crystal reference. Use Value: Avoids clock domain crossing issues via synchronous source routing - improves A/V sync accuracy to <10 μs. |
Equivalent & Alternatives
Cypress CY2545QC021 has two verified functional alternatives with documented differences in voltage support, spread spectrum capability, and I²C address flexibility.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| IDT 8T49N241 | Supports JESD204B subclass 1 deterministic latency; no spread spectrum; requires external EEPROM for configuration | Better suited for high-speed data converter timing where phase alignment > EMI reduction | Select when deterministic sub-nanosecond latency and multi-device synchronization are required over EMI suppression |
| Si5338A-B-GM | Four-output (not eight); integrated crystal option; higher max output frequency (800 MHz); I²C + SPI interface | Preferred for compact, crystal-integrated designs needing >166 MHz outputs (e.g., FPGA transceivers) | Select when board space is constrained and >300 MHz outputs are needed - not suitable for 8-output legacy system replacement |
Compared with IDT 8T49N241 and Si5338A-B-GM, CY2545QC021 uniquely balances eight spread-spectrum outputs, triple-voltage bank independence, and nonvolatile I²C programming - making it optimal for cost-sensitive, EMI-constrained PC and industrial control applications requiring full pin compatibility with legacy Cypress clock trees.
Availability
CY2545QC021 is available at Aetrix Electronics and suitable for PC motherboard design, industrial PLC timing, embedded media gateway development, and networking switch ASIC reference clocking requiring stable component supply and long-term lifecycle assurance.
Supply support for CY2545QC021 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.
CY2545QC021 belongs to Cypress's programmable clock generator product line, engineered specifically for EMI-sensitive, multi-rail embedded systems requiring flexible, software-configurable clock trees with guaranteed glitch-free operation during dynamic frequency scaling.
FAQ
What is the maximum allowable crystal load capacitance for CY2545QC021?
The maximum crystal load capacitance is 18 pF, as specified in the "Recommended Crystal Specification" section of the official datasheet (Document Number: 001-13196 Rev. *I). This value is programmable via I²C register 0x1A[7:0], and exceeding 18 pF may cause startup failure or frequency drift beyond ±50 ppm tolerance.
Can CY2545QC021 generate a 122.88 MHz output for telecom applications?
Yes - CY2545QC021 supports 122.88 MHz via fractional-N synthesis from an 8–48 MHz crystal. Using PLL2 with feedback divider = 12288 and reference divider = 1000 yields exact 122.88 MHz (12.288 × 10), meeting ITU-T G.8262 ePRTC phase noise requirements when configured with low-jitter loop bandwidth.
Is the SSON pin (CLK6/SSON) compatible with 1.8 V logic levels?
No - CLK6/SSON operates at the voltage level of VDD_CLK_B3 (Pin 16), which for CY2545QC021 must be 2.5 V, 3.0 V, or 3.3 V. Driving this pin with 1.8 V logic will result in undefined behavior; a level shifter is required if interfacing with 1.8 V microcontrollers.
Does CY2545QC021 support hot-plug reconfiguration via I²C without resetting outputs?
Yes - I²C writes to registers controlling PLL dividers, spread spectrum, or output enable do not interrupt ongoing clock outputs. Only writes to the global reset register (0x00) or power-down assertion (PD# pin low) cause output stoppage; all other configuration changes occur dynamically with no glitches.
CY2545QC021 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Infineon Technologies
- Series:
- -
- Package/Case:
- 24-UFQFN Exposed Pad
- Packaging:
- Tray
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Fanout Distribution, Fractional N Synthesizer, Multiplexer, Spread Spectrum Clock Generator
- PLL:
- Yes with Bypass
- Input:
- Clock, Crystal
- Output:
- Clock
- Number of Circuits:
- 4
- Ratio - Input:Output:
- 2:8
- Differential - Input:Output:
- No/No
- Frequency - Max:
- 166MHz
- Divider/Multiplier:
- Yes/No
- Voltage - Supply:
- 2.25V ~ 3.6V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 24-QFN (4x4)
CY2545QC021 FAQ
1.How can I place an order for CY2545QC021 through Aetrix?
Please submit a Request for Quotation (RFQ) for CY2545QC021 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for CY2545QC021 reliable?
The price and inventory of CY2545QC021 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CY2545QC021 is usually 5 days.
3.What payment methods are accepted for CY2545QC021?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CY2545QC021 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CY2545QC021?
CY2545QC021 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CY2545QC021 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for CY2545QC021?
For technical support, including CY2545QC021 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CY2545QC021 requirements.
6.How does Aetrix verify that CY2545QC021 is sourced from the original manufacturer or authorized distributors?
All CY2545QC021 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that CY2545QC021 meets industry standards.
7.What is the process for return or replacement of CY2545QC021?
All CY2545QC021 units undergo pre-shipment inspection (PSI). If there is an issue with CY2545QC021, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The CY2545QC021 part is unused and in its original packaging.
Return procedure for CY2545QC021:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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