General Description

The 840N021 is a LVCMOS/LVTTL clock synthesizer designed for

Ethernet applications. The device generates a 125MHz clock signal

from a 25MHz crystal with excellent phase jitter performance. The

device uses IDT’s fourth generation FemtoClock® NG technology for

an optimum of high clock frequency, low phase noise performance

and low power consumption.The device supports 2.5V or 3.3V

voltage supply and is packaged in a small, lead-free (RoHS 6) 8-lead

TSSOP package. The extended temperature range supports

wireless infrastructure, telecommunication and networking end

equipment requirements. The device is a member of the

high-performance clock family from IDT.

Features

• Fourth generation FemtoClock® NG technology

• 125MHz output clock synthesized from a 25MHz fundamental

mode crystal

• One 2.5V or 3.3V LVCMOS/LVTTL clock output

• Crystal interface designed for a 12pF parallel resonant crystal

• RMS phase jitter @ 125MHz, using a 25MHz crystal

(1.875MHz - 20MHz): 0.156ps (maximum)

• RMS phase jitter @ 100MHz, using a 20MHz crystal

(12kHz - 20MHz): 0.451ps (maximum)

• LVCMOS interface level for the output enable input

• Full 2.5V or 3.3V supply voltage

• Lead-free (RoHS 6) packaging

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

• Use replacement part 840N202CKI-dddLF