Infineon Technologies CY22381FXIT

Overview

CY22381FXIT from Cypress Semiconductor is a three-PLL, flash-programmable clock generator in an 8-pin SOIC package operating at 3.3 V. It supports crystal inputs from 8–30 MHz or external clock inputs up to 166 MHz, delivers three independent programmable outputs (CLKA/CLKB/CLKC), and features ultra-wide dividers (11-bit P, 8-bit Q, 7-bit post-divide) for precise frequency synthesis in networking and datacom systems.

For engineers reviewing the CY22381FXIT datasheet, CY22381FXIT pinout, CY22381FXIT application, or CY22381FXIT equivalent, key selection criteria include its field-programmable PLL architecture, glitch-free frequency select via FS pin, on-die linear crystal load capacitors (6–30 pF), low-jitter performance (200 ps peak-to-peak), and configurable power-saving modes (Shutdown, OE, Suspend).

Technical Context

The CY22381FXIT integrates three fully independent PLLs, each with an 11-bit feedback divider (P) and 8-bit reference divider (Q), enabling simultaneous generation of three unrelated output frequencies from a single reference source. Output routing is managed by a 4×3 crosspoint switch that selects among REF, PLL1, PLL2, or PLL3 before applying a 7-bit post-divider.

Its crystal oscillator includes programmable drive strength and on-die linear parallel-plate load capacitors (6–30 pF in 0.375 pF steps), eliminating external capacitors and minimizing frequency drift across temperature, supply, and bias variations. The FS/SUSPEND/OE/SHUTDOWN pin (Pin 8) supports four configurable functions with guaranteed glitch-free transitions during frequency switching.

Key Specifications

Pinout & Package

Package: 8-pin Small Outline Integrated Circuit (SOIC), RoHS-compliant, NiPdAu lead finish (CY22381FXIT variant).

Key Features

Applications

Equivalent & Alternatives

Two verified alternatives provide comparable multi-PLL programmability and industrial temperature support:

Compared with Si5338A-B-GM and ICS843002AGI-01, CY22381FXIT offers true field-programmability in a pin-compatible SOIC package with zero external components for crystal loading, making it optimal for rapid prototyping and legacy board upgrades requiring minimal layout changes.

Availability

CY22381FXIT is available at Aetrix Electronics and suitable for 10G Ethernet line cards, industrial PLC timing modules, optical transport network FEC ASICs, and medical imaging data acquisition systems requiring stable component supply and long-term lifecycle support.

Supply support for CY22381FXIT 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 (PSoC), memory, and timing solutions for industrial, automotive, and communications markets.

The CY22381 product line delivers flash-programmable clock generators targeting applications requiring field-reconfigurable timing with minimal external components - especially in space-constrained networking and datacom equipment.

FAQ

What is the maximum crystal frequency supported by CY22381FXIT?

The CY22381FXIT supports fundamental-mode crystals from 8 MHz to 30 MHz. It does not support overtone crystals or crystals above 30 MHz in crystal-input mode. For higher-frequency references, an external CMOS clock signal up to 166 MHz may be applied directly to XTALIN with XTALOUT left floating.

Can CY22381FXIT generate three different output frequencies simultaneously?

Yes. Its three independent PLLs (PLL1, PLL2, PLL3) each have separate 11-bit P and 8-bit Q dividers, and outputs CLKA, CLKB, CLKC are routed through a 4×3 crosspoint switch. This allows fully independent frequency synthesis - for example, 125 MHz, 156.25 MHz, and 10 MHz - all derived from the same 25 MHz crystal.

How does the FS pin enable glitch-free frequency switching?

The FS pin selects between two pre-programmed register sets controlling PLL1 frequency and CLKA/CLKB post-dividers. Internal logic guarantees atomic register update and phase alignment during transition, preventing clock interruptions or metastability. This is validated in the datasheet under "Frequency Select" and "Glitch-Free Switching" sections.

Is CyClocks RT software required to configure CY22381FXIT?

No - CyClocks RT is optional but strongly recommended. Configuration can be performed via parallel programming interface using standard PROM programmers. However, CyClocks RT automates frequency planning, validates electrical constraints (e.g., P/Q limits, jitter estimates), and generates verified JEDEC files, significantly reducing configuration risk and time-to-market.