Infineon Technologies CY2509ZXC-1T

Overview

CY2509ZXC-1T from Cypress Semiconductor is a Spread Aware™ PLL-based zero-delay clock buffer with ten LVCMOS/LVTTL outputs, designed for DDR SDRAM DIMM applications requiring precise clock distribution at 100–133 MHz. It features 3.3 V operation, <100 ps cycle-to-cycle jitter, <100 ps output-to-output skew, and integrated 25 Ω series damping resistors on all outputs.

For engineers reviewing the CY2509ZXC-1T datasheet, CY2509ZXC-1T pinout, CY2509ZXC-1T application, or CY2509ZXC-1T equivalent, key selection criteria include spread-spectrum timing compatibility, dual output-enable control (OE0:4 and OE5:8), feedback-path trace-matching requirements, and TSSOP-24 package layout constraints for low-skew DIMM clock routing.

Technical Context

The CY2509ZXC-1T implements a PLL-based zero-delay architecture where FBIN is externally connected to FBOUT via a matched-length trace, enabling phase alignment of all Q0–Q9 outputs to the CLK input. Its Spread Aware™ design preserves the frequency modulation profile of SSFTG reference signals to prevent tracking skew in EMI-sensitive systems.

It supports 40–140 MHz output frequencies with 43–58% duty cycle, 2.1 ns rise/2.5 ns fall time (30 pF load), and achieves PLL lock within 1.0 ms. Dual OE pins allow independent shutdown of Q0–Q4 and Q5–Q8 groups, reducing dynamic power and system-level EMI during idle states.

Key Specifications

Pinout & Package

Package: 24-pin Thin Shrink Small Outline Package (TSSOP), lead-free, commercial temperature range (0 °C to +70 °C).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar zero-delay clock buffer applications.

Compared with IDT5V9803APFG and ICS8302AM-01LFT, the CY2509ZXC-1T uniquely delivers Spread Aware™ SSFTG pass-through, integrated 25 Ω termination, and dual OE control-making it the only option qualified for PC100/133 DIMMs using spread-spectrum timing without added layout complexity or performance trade-offs.

Availability

CY2509ZXC-1T is available at Aetrix Electronics and suitable for PC100 DIMM manufacturing, PC133 SDRAM module design, and EMI-sensitive memory subsystem development requiring stable component supply and long-term lifecycle support.

Supply support for CY2509ZXC-1T 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 U.S.-based semiconductor company specializing in programmable system-on-chip, memory, and timing solutions for computing, communications, and industrial markets.

The CY2509/10 product line was developed specifically for high-speed memory module clock distribution, addressing tight skew budgets and EMI reduction needs in DDR SDRAM DIMMs using spread-spectrum clocking.

FAQ

What is the purpose of the FBIN and FBOUT pins?

FBOUT provides a dedicated buffered copy of an internal clock node, intended to connect directly to FBIN. This external feedback loop allows the PLL to align output edges precisely with the CLK input when trace lengths between FBOUT→FBIN and Qx→load are matched. It is mandatory for achieving zero-delay operation and cannot be omitted or shorted.

Can CY2509ZXC-1T operate with a 2.5 V supply?

No. The CY2509ZXC-1T is specified exclusively for 3.3 V ±10% operation. Its internal PLL, output drivers, and input thresholds are designed for 3.3 V logic levels. Applying 2.5 V will result in failure to lock, excessive jitter, or non-functional outputs, as confirmed by DC electrical characteristics and absolute maximum ratings.

How does Spread Aware™ differ from standard zero-delay buffering?

Standard zero-delay buffers filter or distort the frequency modulation of spread-spectrum clock inputs, causing tracking skew between outputs. Spread Aware™ preserves the full SSFTG modulation envelope on all outputs, ensuring synchronized edge placement even under modulated conditions-critical for maintaining EMI reduction benefits in modern PC platforms.

Is external termination required on Q0–Q9 outputs?

No. Each Q0–Q9 output includes a factory-trimmed 25 Ω series damping resistor. This eliminates the need for discrete 25 Ω resistors in series with each output trace, simplifying layout, reducing component count, and improving impedance matching for controlled-impedance PCB routing to DRAM clock inputs.