DATA SHEET

ICS844251BGI-14 REVISION A June 6, 2016

1

©2016 Integrated Device Technology, Inc.

FemtoClock™ Crystal-to-LVDS

Clock Generator

ICS844251I-14

General Description

The ICS844251I-14 is an Ethernet Clock Generator.

The ICS844251I-14 uses an 18pF parallel resonant

crystal over the range of 23.2MHz – 30MHz. For

Ethernet applications, a 25MHz crystal is used. The

device has excellent <1ps phase jitter performance,

over the 1.875MHz – 20MHz integration range. The ICS844251I-14

is packaged in a small 8-pin TSSOP, making it ideal for use in

systems with limited board space.

Features

• One differential LVDS output pair

• Crystal oscillator interface designed for an 18pF, parallel resonant

crystal (23.2MHz – 30MHz)

• Output frequency ranges: 145MHz – 187.5MHz and

580MHz – 750MHz

• VCO range: 580MHz – 750MHz

• RMS phase jitter at 156.25MHz, using a 25MHz crystal

(1.875MHz – 20MHz): 0.53ps (typical)

• Full 2.5V output supply mode

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

• Available in lead-free (RoHS 6) package

• For functional replacement part use 8T49N242

Common Configuration Table

HiPerClockS™

ICS

Inputs

Output Frequency Range

(MHz)

Crystal Frequency (MHz)

FREQ_SEL

M

N

Multiplication Value M/N

25

1

25

1

25

625

26.67

1

25

1

25

666.67

25 (default)

0

25

4

6.25

156.25

1

2

3

4

8

7

6

5

VDDA

GND

XTAL_OUT

XTAL_IN

VDD

Q

nQ

FREQ_SEL

ICS844251I-14

8 Lead TSSOP

4.40mm x 3.0mm x 0.925mm

package body

G Package

Top View

OSC

Phase

Detector

VCO

580MHz - 750MHz

M = ÷25 (fixed)

FREQ_SEL

N

0 (default)

÷4

1

÷1

Pulldown

XTAL_IN

XTAL_OUT

FREQ_SEL

Q

nQ

Block Diagram

Pin Assignment

PRODUCT DISCONTINUATION NOTICE - LAST TIME BUY EXPIRES MAY 6, 2017