Infineon Technologies CY28411ZXC-1

Overview

CY28411ZXC-1 from Cypress Semiconductor is a programmable clock generator compliant with Intel® CK410M specification and designed for Intel Pentium-M CPU platforms. It delivers differential 100-MHz SRC clocks, fixed 96-MHz dot clock, 48-MHz USB clock, 33-MHz PCI clock, and 14.318-MHz reference clock - all from a single 14.318-MHz crystal input. Its I²C interface enables runtime output enable/disable control and spread-spectrum configuration for EMI reduction in notebook motherboard designs.

For engineers reviewing the CY28411ZXC-1 datasheet, CY28411ZXC-1 pinout, CY28411ZXC-1 application, or CY28411ZXC-1 equivalent, key selection criteria include Intel Alviso chipset timing compliance, differential clock pair routing support, I²C register accessibility for dynamic clock gating, and Lexmark-specified spread-spectrum profile for FCC/CE radiated emissions certification.

Technical Context

The CY28411ZXC-1 integrates two PLLs: PLL1 generates the 14.318-MHz reference and feeds PLL2, which synthesizes all high-frequency outputs including CPU, SRC, and DOT96 clocks. Frequency selection is latched via three 3.3V-tolerant FS pins (FS_A/FS_B/FS_C) upon VTT_PWRGD# assertion, enabling stable boot-time CPU frequency configuration (100/133/200/266 MHz).

It supports dual-mode differential outputs (CPUT/CPUC and SRCT/SRCC), configurable stop behavior on CPU_STP# and PCI_STP#, and per-output enable/disable via I²C-accessible control registers (e.g., Byte 0–5). The device uses a parallel-resonance 14.318-MHz crystal with 20-pF load capacitance and requires external trim capacitors calculated per series-capacitance topology.

Key Specifications

Pinout & Package

56-pin SSOP/TSSOP package with 0.5-mm pitch; thermally enhanced layout separates analog (VDDA/VSSA/IREF) and digital power domains to minimize jitter coupling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT 8T49N241 and NB3N3020B, the CY28411ZXC-1 uniquely combines Intel CK410M compliance, differential CPU/SRC outputs, I²C configurability, and Lexmark-specified spread spectrum - making it irreplaceable for certified Alviso-based notebook designs requiring field-upgradable clock management.

Availability

CY28411ZXC-1 is available at Aetrix Electronics and suitable for notebook motherboard timing, Intel Pentium-M platform integration, SATA reference clock distribution, and EMI-sensitive industrial embedded systems requiring stable component supply and long-term lifecycle support.

Supply support for CY28411ZXC-1 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 timing, memory, microcontroller, and connectivity solutions for computing and embedded markets.

The CY28411 product line was engineered specifically for Intel chipset-compliant clock generation in mobile computing platforms, emphasizing low-jitter differential outputs, spread-spectrum EMI reduction, and I²C-based system-level configurability.

FAQ

What crystal specifications are mandatory for CY28411ZXC-1 operation?

The CY28411ZXC-1 requires a 14.31818 MHz AT-cut parallel-resonance crystal with 20-pF load capacitance, maximum 35-ppm initial tolerance, and ≤30 ppm temperature stability. Substituting a series-resonance crystal causes ≥300-ppm frequency error and violates jitter specifications. External trim capacitors must be calculated using series-capacitance topology, not parallel.

How does the VTT_PWRGD# pin control frequency selection and output latching?

VTT_PWRGD# is a level-sensitive strobe that latches the states of FS_A, FS_B, FS_C, and PCIF0/ITP_EN on its falling edge. Once sampled low, all subsequent transitions on those pins are ignored until power cycle. This ensures deterministic CPU frequency selection during processor VTT rail stabilization, preventing metastability in boot-time clock configuration.

Can the I²C interface be used to modify clock outputs during system runtime?

Yes - the I²C interface supports full read/write access to eight control registers enabling real-time enable/disable of any clock output (e.g., disabling unused SRC pairs to reduce power), spread-spectrum on/off toggling, and stop-mode behavior reconfiguration. However, it cannot be used for dynamic frequency changes - only static output control post-initialization.

What is the functional difference between CPUT2_ITP/SRCT7 and CPUC2_ITP/SRCC7 pins?

These pins operate as dual-function differential outputs: when PCIF0/ITP_EN = 1 at VTT_PWRGD# assertion, they deliver CPU2 clock signals (CPUT2/CPUC2); when PCIF0/ITP_EN = 0, they deliver SRC7 clock signals (SRCT7/SRCC7). This allows one pin pair to serve either CPU or serial reference clock roles, reducing pin count and PCB routing complexity in multi-configuration designs.