General Description

The 813N2532I device uses IDT's fourth generation FemtoClock®

NG technology for optimal high clock frequency and low phase noise

performance, combined with a low power consumption and high

power supply noise rejection. The 813N2532I is a PLL based

synchronous multiplier that is optimized for PDH or SONET to

Ethernet clock jitter attenuation and frequency translation.

The 813N2532I is a fully integrated Phase Locked loop utilizing a

FemtoClock NG Digital VCXO that provides the low jitter, high

frequency SONET/PDH output clock that easily meets OC-48 jitter

requirements. This VCXO technology simplifies PLL design by

replacing the pullable crystal requirement of analog VCXOs with a

fixed 27MHz generator crystal. Jitter attenuation down to 10Hz is

provided by an external loop filter. Pre-divider and output divider

multiplication ratios are selected using device selection control pins.

The multiplication ratios are optimized to support most common

clock rates used in PDH, SONET and Ethernet applications. The

device requires the use of an external, inexpensive fundamental

mode 27MHz crystal. The device is packaged in a space-saving

32-VFQFN package and supports commercial temperature range.

Features

• Fourth generation FemtoClock® NG technology

• Two LVPECL output pairs

• Output frequencies: 19.44MHz, 25MHz, 125MHz, 155.52MHz and

156.25MHz

• Two differential inputs support the following input types: LVPECL,

LVDS, LVHSTL, HCSL

• Accepts input frequencies from 8kHz to 38.88MHz including

8kHz, 19.44MHz, 25MHz and 38.88MHz

• Crystal interface optimized for a 27MHz, 10pF parallel resonant

crystal

• Attenuates the phase jitter of the input clock by using a low-cost

fundamental mode crystal

• Customized settings for jitter attenuation and reference tracking

using external loop filter connection

• FemtoClock NG frequency multiplier provides low jitter, high

frequency output

• Absolute pull range: ±100ppm

• Power supply noise rejection (PSNR): -95dB (typical)

• RMS phase jitter @ 156.25MHz, using a 27MHz crystal

(12kHz – 20MHz): 0.6ps (typical)

• RMS phase jitter @ 155.52MHz, using a 27MHz crystal

(12kHz – 20MHz): 0.622ps (typical)

• RMS phase jitter @ 125MHz, using a 27MHz crystal

(12kHz – 20MHz): 0.6ps (typical)

• 3.3V supply voltage

• -40°C to 85°C ambient operating temperature

• Available in lead-free (RoHS 6) package