Infineon Technologies W40S11-02H

Overview

W40S11-02 from Cypress Semiconductor Corporation is a 10-output, skew-controlled CMOS clock buffer designed for SDRAM DIMM clock distribution in mobile systems using Intel's Mobile chipsets. It operates from a single 3.3V supply, delivers rail-to-rail CMOS outputs with 15Ω typical impedance, supports DC–133 MHz input frequencies, and features I²C-based serial configuration. It drives two SDRAM DIMMs with <250 ps output skew and 1–5 ns propagation delay.

For engineers reviewing the W40S11-02 datasheet, W40S11-02 pinout, W40S11-02 application, or W40S11-02 equivalent, key selection criteria include skew tolerance, I²C configurability, output enable control, 3.3V rail-to-rail drive capability, and compatibility with mobile SDRAM timing requirements.

Technical Context

The W40S11-02 implements a low-jitter, ten-channel fanout buffer with per-output enable via I²C register mapping (Data Bytes 0–2) or hardware OE pin. All outputs are phase-aligned to BUF_IN with controlled skew (<±250 ps) and propagation delay (1–5 ns).

It uses internal 250 kΩ pull-up resistors on SDATA, SCLOCK, and OE; supports open-drain I²C bus operation with acknowledge pulses; and provides three-state outputs when OE is low or individual SDRAM outputs are disabled via serial configuration.

Key Specifications

Pinout & Package

Package: 28-pin, 209-mil Shrink Small Outline Package (SSOP), surface-mount, lead-free compatible.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT 74FCT162244ATPA and ON NB3N502DR2G, the W40S11-02 uniquely combines 10-channel skew control, I²C programmability, 15Ω output drive, and dual-DIMM support in a single 3.3 V package-making it irreplaceable for Intel Mobile chipset memory subsystems requiring dynamic clock management.

Availability

W40S11-02 is available at Aetrix Electronics and suitable for mobile notebook memory subsystems, Intel Mobile chipset reference designs, and compact PC/104-Plus SDRAM expansions requiring stable component supply and long-lifecycle support.

Supply support for W40S11-02 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, designs high-performance timing, memory, and programmable logic solutions for computing and communications markets.

The W40S11-02 belongs to Cypress's clock buffer product line, engineered specifically for low-skew, configurable clock distribution in mobile SDRAM memory subsystems interfacing with Intel chipsets.

FAQ

What is the function of the OE pin on the W40S11-02?

The OE (Output Enable) pin is an active-high control input that places all ten SDRAM outputs into high-impedance state when driven low. It features an internal 250 kΩ pull-up resistor to VDD – 0.8 V, ensuring outputs remain enabled at power-up unless actively overridden. This allows hardware-level clock gating independent of I²C configuration.

How does the W40S11-02 achieve ±250 ps output skew?

The W40S11-02 achieves ±250 ps skew through matched internal routing, identical output driver design across all ten channels, and process-compensated layout techniques. Each SDRAMx output undergoes the same propagation path from BUF_IN, with delay variation tightly controlled during silicon characterization across voltage, temperature, and process corners.

Can the W40S11-02 drive DDR SDRAM modules?

No-the W40S11-02 is specified for SDR SDRAM (PC66/PC100/PC133) operation up to 133 MHz with CMOS rail-to-rail outputs. It lacks DDR-specific features such as double-data-rate edge control, differential signaling, or SSTL-2 compliance, and its 15Ω output impedance is tuned for SDR trace loads, not DDR termination schemes.

What happens if the I²C slave address is incorrect during configuration?

If the I²C slave address byte does not match 11010010 (0xD2), the W40S11-02 ignores all subsequent data bytes in that transmission. No registers are updated, and the device continues operating with prior settings or power-on defaults. The ACK pulse is not generated, allowing the master to detect failed writes.