Infineon Technologies CY29973AI

Overview

CY29973AI from Cypress Semiconductor is a 3.3V, 125-MHz multi-output zero-delay buffer IC with integrated PLL, delivering 12 configurable clock outputs and one dedicated feedback output (FB_OUT) for nested clock tree applications. It supports dual reference inputs (PECL or single-ended TCLK), offers 350 ps max output-to-output skew, and operates across -40°C to +85°C in industrial environments.

For engineers reviewing the CY29973AI datasheet, CY29973AI pinout, CY29973AI application, or CY29973AI equivalent, key selection criteria include its VCO lock range (200–480 MHz), glitch-free frequency transitions on SELA/SELB/SELC/VCO_SEL changes, SYNC pulse generation for non-integer clock ratio synchronization, and support for spread-spectrum clocking.

Technical Context

The CY29973AI implements a phase-locked loop with a voltage-controlled oscillator running at 200–480 MHz, divided via three independent banks (QA/QB/QC) each with four outputs and programmable dividers (e.g., /4, /6, /8, /10, /12, /16, /24). Feedback is closed via FB_OUT → FB_IN with divider selection by FB_SEL[2:0] and optional VCO/2 via VCO_SEL.

It provides synchronous edge alignment between QA/QC rising edges using the SYNC output-a low-going one-cycle pulse timed one period before coincident edges-and supports dynamic reference switching (REF_SEL/TCLK_SEL) and per-output freeze control via serial SDATA/SCLK interface without runt pulses.

Key Specifications

Pinout & Package

52-pin TQFP (10 × 10 × 1.0 mm), lead-free, industrial temperature grade. Power pins include VDD (PLL core), VDDC (output buffers), and multiple VSS ground connections with strict 0.1 µF bypass capacitor placement requirement (<0.2" trace length).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPC973 and ICS85310AMLF, the CY29973AI uniquely combines full PLL programmability, SYNC-based cross-bank coordination, and serial power management-making it optimal for adaptive, multi-domain timing architectures where timing precision and configurability are co-prioritized.

Availability

CY29973AI is available at Aetrix Electronics and suitable for high-performance computing clock trees, industrial PLC synchronization, telecom line card timing, and ATE clock synthesis requiring stable component supply and long-term industrial-grade availability.

Supply support for CY29973AI 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) designs high-performance timing, memory, and programmable logic solutions for industrial, automotive, and communications markets.

The CY29973AI belongs to Cypress's zero-delay clock buffer product line, engineered specifically for low-skew, multi-output clock distribution in systems demanding deterministic phase alignment and dynamic reconfiguration capability.

FAQ

What is the function of the SYNC output?

The SYNC output delivers a one-cycle low-going pulse timed precisely one period before coincident rising edges of QA and QC bank outputs. It is generated regardless of their frequency ratio and serves as a deterministic synchronization signal for inter-chip or inter-subsystem coordination-especially valuable when QA and QC clocks have non-integer relationships.

How does the CY29973AI achieve zero delay?

Zero delay is achieved by closing the PLL feedback loop from FB_OUT to FB_IN, causing the PLL to align the rising edge of output clocks with the rising edge of the reference input. Propagation delay is canceled through phase correction, resulting in near-zero net delay-though static phase offset remains dependent on reference frequency and VCO configuration.

Can individual outputs be disabled without affecting others?

Yes-12 of the 14 outputs (all except QC0 and FB_OUT) can be independently frozen via the serial SDATA/SCLK interface. Writing '0' to corresponding bits (D0–D11) stops the output in logic low state without generating runt pulses, enabling fine-grained dynamic power management per clock domain.

Is the CY29973AI compatible with spread-spectrum clocking?

Yes-the device is explicitly designed to accept spread-spectrum modulated reference inputs (via PECL_CLK or TCLK) while maintaining PLL lock and output jitter performance. This compatibility reduces electromagnetic interference without requiring changes to clock tree topology or layout.