General Description

The 845252 is a 3.3V/2.5V CML clock generator designed for

Ethernet applications. The device synthesizes either a 50MHz,

62.5MHz, 100MHz, 125MHz, 156.25MHz, 250MHz or 312.5MHz

clock signal with excellent phase jitter performance. The clock signal

is distributed to two low-skew differential CML outputs. The device is

suitable for driving the reference clocks of Ethernet PHYs. The

device supports 3.3V and 2.5V voltage supply and is packaged in a

small, lead-free (RoHS 6) 32-lead VFQFN package. The extended

temperature range supports telecommunication, wireless

infrastructure and networking end equipment requirements. The

device is a member of the family of High Performance Clock

Solutions from IDT.

Features

• Clock generation of: 50MHz, 62.5MHz, 100MHz, 125MHz,

156.25MHz, 250MHz and 312.5MHz

• Two differential CML clock output pairs

• Crystal interface designed for 25MHz,

18pF parallel resonant crystal

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

(1.875MHz – 20MHz): 400fs (typical), 3.3V

Offset Noise Power

100Hz.................... -102.4 dBc/Hz

1kHz.................... -119.4 dBc/Hz

10kHz................... -124.8 dBc/Hz

100kHz................... -125.7 dBc/Hz

• LVCMOS interface levels for the control inputs

• Full 3.3V and 2.5V supply voltage

• Available in lead-free (RoHS 6) 32 VFQFN package

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

• For functional replacement part use 8T49N241