Analog Devices Inc. AD9571ACPZPEC-R7

Overview

AD9571ACPZPEC-R7 from Analog Devices is a fully integrated Ethernet-optimized clock generator IC with 10 clock outputs: six 25 MHz CMOS, one 33.33 MHz CMOS, one 156.25 MHz LVPECL/LVDS, and two configurable 100/125 MHz LVPECL/LVDS outputs. It features an integer-N PLL with integrated VCO, 0.17 ps rms jitter (1.875–20 MHz @ 156.25 MHz LVDS), and operates from a single 3.3 V supply in −40°C to +85°C industrial range. It serves as the primary timing source for multi-port GbE line cards.

For engineers reviewing the AD9571ACPZPEC-R7 datasheet, AD9571ACPZPEC-R7 pinout, AD9571ACPZPEC-R7 application, or AD9571ACPZPEC-R7 equivalent, key selection criteria include its preset Ethernet-frequency outputs (156.25/125/100/33.33/25 MHz), dual-output format support (LVPECL or LVDS), integrated loop filter, 40-lead 6 mm × 6 mm LFCSP package, and strapping-pin configuration - all critical for deterministic, low-jitter, no-software clock distribution in switch/router PHY timing.

Technical Context

The AD9571ACPZPEC-R7 implements a fixed-configuration integer-N PLL with dedicated PFD, precision charge pump, and low-phase-noise VCO optimized for Ethernet synchronization. Its feedback and output dividers are factory-programmed - no register programming required - and it accepts only a 25 MHz crystal or reference clock on REFCLK or XO pins.

All 10 outputs are hardwired: six identical 25 MHz CMOS clocks (Pins 3,4,29,30,31,32), one 33.33 MHz CMOS (Pin 23), one 156.25 MHz differential pair (Pins 17,18), and two 100/125 MHz differential pairs (Pins 19/20 and 21/22) selected via FREQSEL strapping. The FORCE_LOW pin (Pin 37) allows deterministic disabling of the 33.33 MHz output to prevent jitter coupling into adjacent 125 MHz outputs.

Key Specifications

Pinout & Package

AD9571ACPZPEC-R7 uses a 40-lead 6 mm × 6 mm lead frame chip scale package (LFCSP) with exposed thermal/electrical paddle requiring connection to GND. Pin functions are fixed and non-programmable; configuration is performed solely via strapping pins (REFSEL, FREQSEL, FORCE_LOW).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-output Ethernet clock generator applications.

Compared with Si5338A-D-GM and ICS8430I-01T, AD9571ACPZPEC-R7 delivers the lowest jitter (0.17 ps rms), smallest package (6×6 mm LFCSP), and simplest integration (no I²C, no configuration registers), making it optimal for cost-sensitive, high-density Ethernet line cards where fixed-frequency operation is acceptable.

Availability

AD9571ACPZPEC-R7 is available at Aetrix Electronics and suitable for Ethernet switches, 10GbE line cards, and PCIe storage controllers requiring stable component supply, long-term lifecycle assurance, and guaranteed traceability.

Supply support for AD9571ACPZPEC-R7 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

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with over 50 years of innovation in precision timing, data conversion, and RF technologies.

The AD9571ACPZPEC-R7 belongs to Analog Devices' Ethernet-optimized clock generator product line, designed specifically to replace discrete oscillator + fanout buffer solutions in carrier-grade networking equipment with a single-chip, low-jitter, zero-configuration timing IC.

FAQ

What is the primary reference input requirement for AD9571ACPZPEC-R7?

The AD9571ACPZPEC-R7 requires a 25 MHz reference - either a 25 MHz crystal connected across Pins 6 and 7 (XO), or a 25 MHz CMOS clock applied to Pin 8 (REFCLK). REFSEL pin selects between these sources. No other input frequencies are supported; the device is hardwired for Ethernet-standard timing only.

Can AD9571ACPZPEC-R7 generate 100 MHz and 125 MHz simultaneously?

Yes, AD9571ACPZPEC-R7 can deliver both 100 MHz and 125 MHz simultaneously: Pins 19/20 output one frequency while Pins 21/22 output the other, as defined by the FREQSEL pin state (logic 0 = 125/125, logic 1 = 100/100, NC = 125/100). This enables mixed-interface designs such as 125 MHz for GbE PHYs and 100 MHz for PCIe endpoints on the same board.

How does FORCE_LOW affect AD9571ACPZPEC-R7 timing performance?

Asserting FORCE_LOW (Pin 37) forces the 33.33 MHz CMOS output (Pin 23) to logic low, eliminating its switching noise. This is critical when FREQSEL = 0 (125 MHz on Pins 21/22), as the 33.33 MHz output's proximity otherwise degrades 125 MHz jitter by up to 1.2 ps rms. AD9571ACPZPEC-R7's design explicitly includes this pin to preserve low-jitter integrity in high-density layouts.

Is AD9571ACPZPEC-R7 pin-compatible with other members of the AD957x family?

No, AD9571ACPZPEC-R7 is not pin-compatible with AD9572 or AD9573. While sharing the same 40-lead LFCSP footprint, pin functions differ significantly - e.g., AD9572 has different output allocations and lacks FORCE_LOW. Board layout must be designed specifically for AD9571ACPZPEC-R7; no drop-in replacement exists within the family.

What is the power dissipation difference between LVDS and LVPECL operation of AD9571ACPZPEC-R7?

AD9571ACPZPEC-R7 dissipates 480–600 mW in LVDS mode and 690–860 mW in LVPECL mode. The 210–260 mW increase in LVPECL results from higher output stage current; however, LVPECL delivers lower jitter (0.22 ps rms vs. 0.41 ps rms at 125 MHz), making it preferred for jitter-critical XAUI or SFI-5 interfaces where thermal headroom permits.