Infineon Technologies CY25823ZXC

Overview

CY25823ZXC from Cypress Semiconductor is a spread-spectrum differential clock generator IC with PLL-based frequency synthesis, supporting 96 MHz or 100 MHz output frequencies, 200 ps RMS jitter, I²C programmability, and Lexmark spread-spectrum modulation for EMI reduction in high-speed digital systems such as PCIe Gen2 reference clocks and SATA host controllers.

For engineers reviewing the CY25823ZXC datasheet, CY25823ZXC pinout, CY25823ZXC application, or CY25823ZXC equivalent, key selection criteria include differential LVDS-compatible output drive (0.7 V), hardware/software-selectable spread spectrum mode, 3.3 V operation, 250 µA power-down current, and TSSOP-16 package compatibility with board-level timing constraints.

Technical Context

The CY25823ZXC implements a phase-locked loop (PLL) architecture with a voltage-controlled oscillator (VCO), feedback divider (M/N), and post-divider to generate precise 96 MHz or 100 MHz differential clock outputs from a 14.31818 MHz single-ended reference input. It supports both center-spread and down-spread modulation modes with configurable spread percentages up to ±1.65%.

Control is provided via either hardware pins (S[3:1], REFOUT/SEL, PWRDWN) or I²C interface (SCLK/SDATA), enabling dynamic reconfiguration of spread enable, spread select [3:0], CLKOUT enable, and charge pump settings. The device integrates separate analog (VDDA/VSSA) and digital (VDD/VSS) power domains to minimize noise coupling into the PLL.

Key Specifications

Pinout & Package

Package: 16-pin TSSOP (Thin Shrink Small Outline Package), 4.4 mm × 5.0 mm body, 0.65 mm pitch, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar spread-spectrum clock generator applications.

Compared with IDT 8T49N241 and ON Semi NB3N502, the CY25823ZXC uniquely balances hardware configurability (pin-strapped frequency/spread), low-power operation (250 µA), and proven Lexmark EMI suppression-making it optimal for PCIe/SATA timing where design flexibility and regulatory compliance are jointly critical.

Availability

CY25823ZXC is available at Aetrix Electronics and suitable for PCIe Gen2 reference clocking, SATA II host controller timing, embedded DisplayPort sources, and industrial Ethernet switch timing requiring stable component supply and long-term lifecycle support.

Supply support for CY25823ZXC 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) designs high-performance timing, memory, and programmable logic solutions for automotive, industrial, and communications markets.

The CY25823 belongs to Cypress's CK-SSCD spread-spectrum clock generator product line, engineered specifically to meet stringent EMI requirements in high-speed serial interface applications without sacrificing jitter performance or design flexibility.

FAQ

What is the function of the REFOUT/SEL pin after power-up?

After power-up, REFOUT/SEL transitions from a frequency-select input to a 14.31818 MHz reference clock output. This dual-role pin provides a stable local reference for companion devices (e.g., audio codecs or secondary PLLs) without requiring an additional oscillator, reducing BOM count and board area.

How does the IREF pin set CLKOUT drive strength?

The IREF pin connects to a precision 475 Ω resistor tied to VSSIREF; this resistor sets the internal current source that defines the differential output swing (0.7 V) and edge rate of CLKOUT/CLKOUT#. Deviation from 475 Ω alters output amplitude and may violate LVDS signaling margins.

Can spread spectrum be disabled during system operation?

Yes-via I²C register write to Byte 0, Bit 1 (Spread Enable). Setting this bit to '0' disables modulation while preserving output frequency and phase continuity. This allows real-time EMI testing (with/without spread) using the same hardware configuration.

Why are separate VDDA and VSSA pins required?

VDDA and VSSA isolate the PLL's analog circuitry-including the VCO, charge pump, and phase detector-from digital switching noise on VDD/VSS. This separation prevents supply-induced jitter degradation and ensures the 200 ps RMS jitter specification is maintained under full-load digital activity.