Infineon Technologies CY28442ZXC

Overview

CY28442ZXC from Cypress Semiconductor is a programmable clock generator IC compliant with Intel® CK410M for Pentium-M platforms, delivering differential CPU clocks (up to 200 MHz), 100-MHz/96-MHz spread-spectrum SRC clocks, 33-MHz PCI, 48-MHz USB, and 96-MHz dot clocks in a single 56-pin TSSOP package.

For engineers reviewing the CY28442ZXC datasheet, CY28442ZXC pinout, CY28442ZXC application, or CY28442ZXC equivalent, this device supports I²C-configurable clock enable/disable, per-output spread-spectrum control, frequency-select input latching via VTT_PWRGD#, and SATA-optimized differential serial reference clock outputs.

Technical Context

The CY28442ZXC integrates four independent PLLs: PLL1 for CPU clock synthesis, PLL2 for PCI/REF generation, PLL4 for 96/100-MHz SS clock, and a fixed-divider path for USB and dot clocks. All differential outputs meet LVDS-compatible swing and skew specifications per Intel CK410M timing requirements.

It implements a dual-mode clock enable architecture: hardware-controlled stop via CPU_STP# and PCI_STP#, plus software-configurable per-output enable/disable via SMBus registers (Bytes 0–5). Frequency selection is latched on VTT_PWRGD# assertion using three FS inputs, supporting eight discrete CPU frequencies from 100 MHz to 200 MHz.

Key Specifications

Pinout & Package

56-pin Thin Shrink Small Outline Package (TSSOP) with exposed pad omitted; pin 1 marked by beveled corner; 0.5-mm pitch; body height 1.2 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT 87011AGLFT and ICS954202AF, the CY28442ZXC uniquely combines Intel CK410M-compliant CPU clock synthesis, SATA-optimized differential SRC, and Lexmark-validated spread spectrum in a 56-pin TSSOP-making it irreplaceable for Alviso-based designs requiring full feature parity.

Availability

CY28442ZXC is available at Aetrix Electronics and suitable for desktop motherboard design, mobile Pentium-M platform integration, flat-panel display timing, and SATA reference clocking requiring stable component supply and long-term industrial availability.

Supply support for CY28442ZXC 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) is a U.S.-based semiconductor company specializing in timing, memory, and programmable solutions for computing and communications infrastructure.

The CY28442 belongs to Cypress's CK410M-compliant clock generator product line, engineered specifically to replace discrete clock trees in Intel Pentium-M desktop platforms while meeting stringent EMI and skew requirements.

FAQ

What is the function of the VTT_PWRGD# pin on CY28442ZXC?

VTT_PWRGD# is a level-sensitive strobe that latches the states of FS_A, FS_B, FS_C, ITP_EN, and 96_100_SEL inputs upon its active-low assertion. After latching, it transitions to a real-time power-down control signal. It must be asserted after VTT supply stabilization but before clock initialization to ensure correct frequency configuration.

Can CY28442ZXC generate both 96 MHz and 100 MHz spread-spectrum clocks simultaneously?

No. The 96/100-MHz spread-spectrum clock pair (pins 17/18) operates at a single frequency selected by PCIF1/96_100_SEL (pin 9): logic high = 100 MHz, logic low = 96 MHz. Both frequencies use identical Lexmark-optimized modulation profiles, but concurrent operation at different frequencies is not supported.

How is the SATA reference clock output configured on CY28442ZXC?

The SATA-optimized output is the SRCT4_SATA/CPUC4_SATA differential pair (pins 26/27). It delivers a 100-MHz clock with <1.5 ps RMS jitter and is enabled by default. Its stoppability is controlled independently via SMBus register Byte 0 bit 4, and it is unaffected by CPU_STP# or PCI_STP# signals.

Does CY28442ZXC support dynamic frequency switching after power-up?

No. CPU frequency is determined solely by the FS_A/B/C logic levels sampled once at VTT_PWRGD# assertion. Subsequent changes to FS inputs have no effect. Dynamic scaling requires external reconfiguration of the CPU's front-side bus and is handled by the processor-not the CY28442ZXC-which provides static, locked clock outputs after initialization.