Infineon Technologies CY2309ZC-1H

Overview

CY2309ZC-1H from Cypress Semiconductor is a 3.3V zero-delay clock buffer IC with PLL-based architecture, designed to distribute high-speed reference clocks across nine low-skew outputs (4+4+1 banked configuration) in CPU, PCI, and SDRAM timing systems. It operates from 10 MHz to 133 MHz, delivers ≤85 ps typical output-to-output skew, supports 5V-tolerant REF input, and features test-mode bypass of the PLL for system validation.

For engineers reviewing the CY2309ZC-1H datasheet, CY2309ZC-1H pinout, CY2309ZC-1H application, or CY2309ZC-1H equivalent, key selection criteria include its high-drive capability (1.5 ns rise/fall time), industrial temperature support (–40°C to +85°C), bank-selectable output control, and guaranteed <700 ps device-to-device skew in multi-chip clock trees.

Technical Context

The CY2309ZC-1H integrates an on-chip PLL with internal feedback routed from the CLKOUT pin, enabling precise zero-input-output delay when all outputs-including CLKOUT-are equally loaded. Its dual-bank output structure (Bank A: CLKA1–CLKA4; Bank B: CLKB1–CLKB4) is controlled by S1/S2 select inputs, allowing independent three-state control or direct pass-through of REF for test mode.

Unlike the base -1 variant, the -1H version delivers faster edge rates (1.5 ns vs. 2.5 ns), lower cycle-to-cycle jitter (60 ps typical vs. 70 ps), and higher drive strength (±12 mA output current), making it suitable for demanding high-frequency, low-skew applications such as Pentium-class motherboard clock distribution and DDR memory subsystems.

Key Specifications

Pinout & Package

Package: 16-pin 4.4-mm TSSOP (lead pitch: 0.65 mm), RoHS-compliant, surface-mount compatible.

Key Features

Applications

Equivalent & Alternatives

Two validated alternatives exist for CY2309ZC-1H in industrial-temperature, high-drive clock buffer applications:

Compared with IDT 8T49N241 and NB3N3020B, CY2309ZC-1H uniquely combines true zero-delay operation, industrial temperature rating, bank-selectable outputs, and PLL bypass-all in a cost-optimized TSSOP package-making it optimal for legacy-compatible, high-reliability clock replication.

Availability

CY2309ZC-1H is available at Aetrix Electronics and suitable for Pentium-class motherboard clock distribution, PCI bus timing synchronization, and industrial networking switch fabric timing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CY2309ZC-1H 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 timing, memory, and microcontroller solutions for industrial, automotive, and communications markets.

The CY2309 product line was engineered specifically for cost-sensitive, high-reliability clock distribution in x86 computing and PCI-based systems-emphasizing zero-delay fidelity, multi-bank flexibility, and industrial temperature robustness.

FAQ

What is the purpose of the CLKOUT pin on CY2309ZC-1H?

The CLKOUT pin provides internal feedback to the PLL and must be loaded identically to all other outputs to achieve zero input-output propagation delay. Even if unused, it requires a capacitive load matching the other outputs (10 pF for 100–133 MHz, 30 pF below 100 MHz) to maintain phase alignment and minimize skew.

How does the S1/S2 select logic affect output behavior?

S1 and S2 configure four operating modes per the CY2309 datasheet table: (0,0) three-states both banks; (0,1) enables Bank A only; (1,0) enables both banks with REF passed directly to CLKOUT (PLL bypass); (1,1) enables both banks with PLL active. This enables in-system test and dynamic power gating.

Can CY2309ZC-1H operate at 133 MHz with 30 pF load?

No-133 MHz operation requires ≤10 pF load per output, as specified in the switching characteristics table. At 30 pF, maximum supported frequency is 100 MHz. Exceeding the load limit degrades edge rate, increases jitter (>200 ps), and risks PLL unlock or duty cycle distortion beyond 40–60%.

Is the REF input truly 5V-tolerant under all conditions?

Yes-the REF pin accepts DC voltages up to 7 V and is rated for 5V logic levels regardless of VDD. Its threshold is VDD/2, and it includes internal protection circuitry. However, AC input slew rate must remain within datasheet limits (≤1 V/ns) to avoid metastability or false triggering.