General Description

The 8T39S08A is a high-performance clock fanout buffer. The input

clock can be selected from two differential inputs or one crystal input.

The internal oscillator circuit is automatically disabled if the crystal

input is not selected. The crystal pin can be driven by a single-ended

clock. The selected signal is distributed to eight differential outputs

which can be configured as LVPECL, LVDS and HCSL outputs. In

addition, an LVCMOS output is provided. All outputs can be disabled

into a high-impedance state. The device is designed for a signal

fanout of high-frequency, low phase-noise clock and data signal. The

outputs are at a defined level when inputs are open or tied to ground.

It is designed to operate from a 3.3V or 2.5V core power supply, and

either a 3.3V or 2.5V output operating supply

Features

• Two differential reference clock input pairs

• Differential input pairs can accept the following input levels:

LVPECL, LVDS, HCSL, HSTL and Single-ended

• Crystal Oscillator Interface

• Crystal input frequency range: 10MHz to 40MHz

• Maximum Output Frequency

LVPECL - 2GHz

LVDS - 2GHz

HCSL - 250MHz

LVCMOS - 250MHz

• Two banks, each has four differential output pairs that can be

configured as LVPECL or LVDS or HCSL

• One single-ended reference output with synchronous enable to

avoid clock glitch

• Output skew: 80ps (maximum)

(Bank A and Bank B at the same output level)

• Part-to-part skew: 200ps (typical)

• Additive RMS phase jitter@ 156.25MHz, (12kHz - 20MHz):

34.7fs (typical), 3.3V/ 3.3V

• Supply voltage modes:

VDD/VDDO

3.3V/3.3V

3.3V/2.5V

2.5V/2.5V

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

• Lead-free (RoHS 6) packaging