Infineon Technologies W234X

Overview

The W234 from Cypress Semiconductor Corporation is a dual-channel differential clock generator for Direct Rambus™ memory subsystems, delivering synchronized RSL-level clocks at up to 1.6 Gb/s serial data transfer rate. It supports PLL-based frequency multiplication (Refclk × A/B), phase alignment via distributed DDLL architecture, and power-managed outputs with active-low STOP# and PWR_DWN# control - deployed in Intel® architecture platforms with CY2210-2/3, CY2215, W133, W158–W167B.

For engineers reviewing the W234 datasheet, W234 pinout, W234 application, or W234 equivalent, key selection criteria include its 3.3 V ±0.165 V supply tolerance, 0°C to +70°C operating range, 40/60% worst-case output duty cycle, Rambus signaling level (RSL) outputs, and support for gear-ratio synchronization between PCLK/M and SYNCLKN/N domains.

Technical Context

The W234 implements a PLL-based clock synthesis core coupled with a distributed delay-locked loop (DDLL) for phase alignment across the Rambus Channel. Its phase detector compares PCLKM0/1 and SYNCLKN0/1 inputs (both derived from gear-ratio-divided system clocks) to drive a phase aligner that adjusts the PLL output (Busclk) until rising edges align within tERR,PD specification.

It supports three operational modes - Normal (full PLL + phase alignment), Bypass (PLL output only, no alignment), and Test (REFCLK passed directly to outputs) - selected via S0–S2 pins. Power management includes Clk Stop (Hi-Z outputs) and full Power-Down (GND outputs, internal logic disabled), both controlled by dedicated active-low inputs.

Key Specifications

Pinout & Package

Package: 28-pin, 173-mil TSSOP (thin shrink small outline package) with exposed thermal pad not specified - surface-mount compatible for high-density motherboard layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Direct Rambus clock generation applications.

Compared with W158 and CY2215, the W234 uniquely delivers dual-channel RSL outputs with integrated DDLL-based phase alignment - essential for latency-critical Intel 8xx-platform RDRAM subsystems where PCLK/SYNCLK domain crossing must occur without added pipeline stages.

Availability

W234 is available at Aetrix Electronics and suitable for desktop memory subsystems, Intel Pentium III platforms, and mobile RDRAM module designs requiring stable component supply and legacy Rambus timing compliance.

Supply support for W234 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 Corporation, now part of Infineon Technologies, designed high-performance timing, memory interface, and programmable logic solutions for computing and communications markets.

The W234 belongs to Cypress's Direct Rambus Clock Generator (DRCG) product line, engineered specifically to meet Rambus Inc.'s stringent phase-alignment, signal integrity, and power management requirements for RDRAM-based systems.

FAQ

What is the function of the MULT0–MULT2 pins on the W234?

MULT0–MULT2 are digital inputs that configure the PLL's feedback (A) and prescaler (B) dividers to set the output Busclk frequency as REFCLK × A/B. Eight valid combinations are defined in Table 1 - e.g., MULT2:0 = 000 selects A=4, B=1 for 4× multiplication. These pins must be stable before or during Power-Down mode to avoid undefined PLL behavior.

How does the W234 achieve zero-latency data transfer between PCLK and SYNCLK domains?

By comparing PCLKM (PCLK/M) and SYNCLKN (SYNCLK/N) at its internal phase detector, the W234 adjusts the Busclk phase via its phase aligner until rising edges align within 50 ps. When PCLK/M and SYNCLKN frequencies match (e.g., 33 MHz), this alignment allows direct register-to-register handoff across domains without added synchronization registers or latency penalties.

Can the W234 operate without connecting PCLKM and SYNCLKN inputs?

Yes - if gear-ratio synchronization is not required, PCLKM0/1 and SYNCLKN0/1 must be tied to GND per datasheet guidance. In this configuration, the W234 operates in free-running PLL mode, generating Busclk based solely on REFCLK and MULT0–2 settings, with no phase alignment to external system clocks.

What is the purpose of VDDIR and VDDIPD pins, and how should they be connected?

VDDIR (Pin 1) supplies the reference voltage for REFCLK input threshold detection (1.5 V typical); VDDIPD (Pin 12) sets the threshold for PCLKM/SYNCLKN/STOP# inputs. Both must be connected to clean, low-noise 3.3 V supplies - VDDIPD should match the memory controller's output voltage rail to ensure compatible logic thresholds for phase detector inputs.