Skyworks Solutions Inc. CY28442ZXC-2T

Overview

CY28442ZXC-2T from Silicon Labs is a programmable clock generator IC designed specifically for Intel® Alviso chipset platforms, delivering synchronized differential clock outputs including 100 MHz SRC, 96 MHz dot clock, 48 MHz USB, and 33 MHz PCI. It integrates three PLLs, supports I²C configuration, and operates from a single 3.3 V supply in a 56-pin TSSOP package for notebook motherboard timing applications.

For engineers reviewing the CY28442ZXC-2T datasheet, CY28442ZXC-2T pinout, CY28442ZXC-2T application, or CY28442ZXC-2T equivalent, key selection criteria include Intel CK410M compliance, selectable CPU frequencies (100/133/166/200 MHz), spread-spectrum control for EMI reduction, differential output drive capability, and SMBus register-based clock enable/disable per channel.

Technical Context

The CY28442ZXC-2T implements three independent PLLs: PLL1 generates CPU clocks (100–200 MHz), PLL2 produces fixed 96/100 MHz spreadable differential clocks for flat-panel displays, and PLL3 delivers 48 MHz USB and 33 MHz PCI clocks. All PLLs share a 14.318 MHz parallel-resonant crystal reference.

It supports hardware-strapped frequency selection via FS_A/FS_B/FS_C pins sampled at VTT_PWRGD# assertion, plus dynamic control via SMBus (slave address 0xD2) for per-output enable/disable, spread-spectrum tuning (±0.25% to ±1.5%), and CLKREQ#-driven SRC clock gating with glitch-free restart within 2–6 clock periods.

Key Specifications

Pinout & Package

Package: 56-pin TSSOP (7.0 mm × 12.5 mm, 0.5 mm pitch), RoHS-compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICS9LPR503AGT and PI6C20400LEX, the CY28442ZXC-2T uniquely integrates CPU PLL, display dot clock, USB clock, and spread-spectrum control in one device - reducing system-level timing complexity and enabling full Alviso platform compliance without supplemental clock ICs.

Availability

CY28442ZXC-2T is available at Aetrix Electronics and suitable for notebook motherboard design, flat-panel display interface, SATA reference clock distribution, and USB 2.0 host controller timing requiring stable component supply across production lifecycles.

Supply support for CY28442ZXC-2T 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

Silicon Labs is a fabless semiconductor company specializing in timing, wireless, and sensor solutions, with leadership in precision clock generation and low-power mixed-signal ICs.

The CY28442ZXC-2T belongs to Silicon Labs' CK410M-compliant clock generator product line, engineered to replace multiple discrete oscillators in Intel mobile platforms while delivering EMI-reduced, configurable, and system-synchronized timing.

FAQ

What is the primary function of the CY28442ZXC-2T in Intel Alviso-based systems?

The CY28442ZXC-2T serves as the central clock generator for Intel Alviso chipset platforms, synthesizing and distributing multiple synchronized clock domains - including CPU (100–200 MHz), SRC (100 MHz), dot clock (96 MHz), USB (48 MHz), and PCI (33 MHz) - all from a single 14.318 MHz crystal reference. Its design ensures full CK410M compliance and eliminates the need for discrete oscillators across the motherboard.

Does the CY28442ZXC-2T support spread-spectrum clocking, and how is it configured?

Yes, the CY28442ZXC-2T supports spread-spectrum clocking on its 96/100 MHz differential outputs. Modulation depth (±0.25% to ±1.5%) and center-spread mode are configured via SMBus register Byte 9 (bits S3–S0 and 96_100 SS Enable). Hardware selection (96_100_SEL pin) or software control (Byte 9 bit 3) determines whether frequency is set by pin strap or register write.

How does the CY28442ZXC-2T handle power sequencing with Intel VRMs?

The CY28442ZXC-2T uses the VTT_PWRGD# pin as a dual-function strobe: during power-up, it latches FS_A/B/C and ITP_EN states when asserted LOW; afterward, it becomes an active-HIGH PD (power-down) input. This enables synchronized startup with Intel VRMs and clean, glitch-free shutdown before VDD removal - critical for Alviso platform reliability.

Can the CY28442ZXC-2T generate both CPU and SRC clocks simultaneously, and what are the constraints?

Yes, the CY28442ZXC-2T generates CPU and SRC clocks concurrently using independent PLLs (PLL1 for CPU, PLL2 for SRC). However, CPU frequency selection (100/133/166/200 MHz) is fixed at power-up via FS_A/B/C straps, while SRC outputs remain fully configurable via SMBus. The two PLLs share the same 14.318 MHz crystal but operate autonomously to avoid cross-coupling.

What crystal specifications are required for stable operation of the CY28442ZXC-2T?

The CY28442ZXC-2T requires a 14.31818 MHz parallel-resonant AT-cut crystal with 20 pF load capacitance, ±35 ppm initial tolerance, ±30 ppm stability over 0–85°C, and ≤5 pF shunt capacitance. Substituting a series-resonant crystal will cause ≥300 ppm frequency error and violate timing specifications - confirmed in Silicon Labs Document #38-07691 Rev. *B.