Infineon Technologies CY7B9950AXCT

Overview

CY7B9950AXCT from Cypress Semiconductor is a 2.5/3.3 V, 200 MHz multi-phase PLL clock buffer with eight LVTTL outputs, programmable phase skew (±7.5 ns in 625/1250 ps steps), 50 ps typical output-output skew, and split output bank power supplies enabling mixed-voltage clock distribution in high-speed computing and telecom clock trees.

For engineers reviewing the CY7B9950AXCT datasheet, CY7B9950AXCT pinout, CY7B9950AXCT application, or CY7B9950AXCT equivalent, key selection criteria include output phase adjustability, bank-specific VDDQ supply flexibility, edge-selectable synchronization (rising/falling), selectable drive strength (±12 mA / ±24 mA), and spread spectrum compatibility for EMI reduction.

Technical Context

The CY7B9950AXCT integrates a voltage-controlled oscillator (VCO) with frequency range selection via FS pin (L/M/H modes), supporting 24–200 MHz PLL operation. It implements four independent output banks (1Q–4Q), each with configurable divider ratios (×1/÷2/÷4) and discrete phase offsets determined by nF[1:0] settings.

Phase alignment is achieved through programmable skew per bank (–4tU to +4tU), where tU scales inversely with nominal frequency and FS-selected multiplication factor (MF = 8–32). Synchronization edge (PE/HD pin) and output enable (sOE#) are fully synchronous to REF, preserving timing integrity during dynamic control.

Key Specifications

Pinout & Package

32-pin TQFP (7 mm × 7 mm, 0.8 mm pitch), RoHS-compliant, with exposed thermal pad. Power pins distributed across VDD (core logic), VDDQ1/VDDQ3/VDDQ4 (bank-specific I/O supplies), and multiple VSS ground connections for noise isolation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-phase PLL clock buffer applications.

Compared with IDT5V9885NLGI and NB3N502DR2G, the CY7B9950AXCT uniquely supports mixed-voltage I/O per bank, fine-grained phase deskew, and synchronous output gating-making it optimal for high-density, multi-standard clock distribution where timing margin and power domain isolation are critical.

Availability

CY7B9950AXCT is available at Aetrix Electronics and suitable for high-speed server memory interfaces, PCI Express Gen2 clock distribution, and telecom line card timing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CY7B9950AXCT 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 fabless semiconductor company specializing in high-performance timing, memory, and programmable logic solutions for computing, communications, and industrial markets.

The RoboClock® product line was designed specifically for high-speed, multi-phase clock distribution in systems demanding precise skew control, flexible voltage operation, and robust PLL performance-targeting server, networking, and FPGA-based platforms.

FAQ

What is the function of the TEST pin, and how does it affect normal operation?

The TEST pin is a three-level input that disables the PLL when held at MID or HIGH, routing REF directly to Banks 1–2 and through dividers to Banks 3–4. For normal PLL operation, TEST must be held LOW. This mode preserves full frequency synthesis, phase adjustment, and feedback functionality-critical for zero-delay or multiplied clock generation.

Can CY7B9950AXCT generate both 2.5 V and 3.3 V outputs simultaneously?

Yes. The device supports simultaneous 2.5 V and 3.3 V outputs via independent VDDQ1 (Banks 1–2), VDDQ3 (Bank 3), and VDDQ4 (Bank 4) supplies. Core VDD must equal or exceed all VDDQ levels. This architecture eliminates level shifters in mixed-voltage clock trees, reducing BOM count and signal integrity risk.

How does the sOE# pin behave during synchronous output disable?

When sOE# is HIGH, all outputs except 2Q0 and 2Q1 are driven low (for PE/HD = H or M); 2Q0/2Q1 remain active to sustain PLL lock via feedback. This synchronous gating avoids metastability and preserves phase alignment-enabling clean clock stop/start in power-managed systems without re-lock delay.

What are the valid settings for FS pin, and how do they impact PLL performance?

The FS pin selects PLL frequency range: L (24–50 MHz), M (48–100 MHz), or H (96–200 MHz). Each setting determines the multiplication factor (MF = 32/16/8) used to calculate phase step size (tU = 1/(fNOM × MF)). Selecting H mode enables 200 MHz operation and 1250 ps skew steps; L mode provides finest resolution (625 ps) at lower frequencies.