Description
The 813N2532 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 813N2532 is a PLL based
synchronous multiplier that is optimized for PDH or SONET to
Ethernet clock jitter attenuation and frequency translation.
The 813N2532 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 at 156.25MHz, using a 27MHz crystal
(12kHz – 20MHz): 0.64ps (typical)
• RMS phase jitter at 155.52MHz, using a 27MHz crystal
(12kHz – 20MHz): 0.64ps (typical)
• RMS phase jitter at 125MHz, using a 27MHz crystal
(12kHz – 20MHz): 0.66ps (typical)
• 3.3V supply voltage
• 0°C to 70°C ambient operating temperature
• Lead-free (RoHS 6) packaging