Infineon Technologies CY25823ZXCT

Overview

CY25823ZXCT from Cypress Semiconductor is a spread-spectrum differential clock generator IC with PLL-based frequency synthesis, supporting 96 MHz or 100 MHz output, 200 ps RMS jitter, I²C programmability, and Lexmark spread-spectrum modulation for EMI reduction in high-speed digital systems.

For engineers reviewing the CY25823ZXCT datasheet, CY25823ZXCT pinout, CY25823ZXCT application, or CY25823ZXCT equivalent, key selection criteria include differential LVDS-compatible output drive, hardware- or software-selectable spread mode (down/center), 3.3 V operation, and low 250 µA power-down current for thermal and noise-sensitive timing subsystems.

Technical Context

The CY25823ZXCT integrates a phase-locked loop (PLL) with a voltage-controlled oscillator (VCO), feedback divider, and post-divider to generate precise differential clock outputs from a 14.131818 MHz single-ended reference input. It supports both hardware (S[3:1] pins) and software (I²C) configuration of spread-spectrum parameters.

Its dual-mode spread control enables down-spread (0.65–3.30%) or center-spread (±0.25–±1.65%) modulation via configurable SS[3:0] bits and charge pump settings (Byte1[1:0]), while maintaining strict AC timing compliance during transitions between spread modes.

Key Specifications

Pinout & 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 CY25823ZXCT uniquely balances programmability (I²C + hardware pins), ultra-low power-down current (250 µA), and certified Lexmark spread-spectrum performance in a standard TSSOP footprint-making it optimal for mid-volume industrial and communications designs requiring field-tunable EMI control.

Availability

CY25823ZXCT is available at Aetrix Electronics and suitable for PCIe Gen2 clock distribution, SATA host controller timing, and DDR3 memory interface applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for CY25823ZXCT 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 microcontroller solutions for industrial, automotive, and communications markets.

The CY25823 belongs to Cypress's CK-SSCD spread-spectrum clock generator product line, engineered specifically to reduce electromagnetic interference in high-speed digital systems without compromising timing accuracy or increasing board area.

FAQ

What is the function of the REFOUT/SEL pin during normal operation?

The REFOUT/SEL pin serves a dual role: at power-up, its logic level (pulled up or down) selects 100 MHz or 96 MHz output frequency; after initialization, it functions as a 14.31818 MHz reference clock output. This dual behavior eliminates the need for an external reference oscillator in systems requiring a secondary timing source.

How does the IREF resistor affect CLKOUT/CLKOUT# performance?

A precision 475 Ω resistor between IREF and VSSIREF sets the output driver current, directly controlling slew rate, rise/fall times, and differential amplitude (0.7 V typical). Deviations from this value cause output swing variation and potential signal integrity issues on controlled-impedance traces, so tight tolerance (±1%) is recommended.

Can spread spectrum be disabled after power-up?

Yes-spread spectrum can be disabled dynamically via I²C by clearing the Spread Enable bit (Byte0[1]) while retaining all other register settings. The device maintains PLL lock and output frequency stability during disable/enable transitions, with no glitch or phase discontinuity on CLKOUT/CLKOUT#.

What is the minimum pulse width requirement for the PWRDWN signal?

The PWRDWN signal requires a minimum high pulse width of 100 ns to reliably enter power-down mode. Cypress specifies no minimum low pulse width; however, the device requires ≥1 ms after deassertion to fully restore output operation and achieve stable PLL lock before valid clock edges appear on CLKOUT/CLKOUT#.