General Description
The 851021 is a 1-to-21 Differential HCSL Fanout Buffer. The
851021 is designed to translate any differential signal levels to
differential HCSL output levels. An external reference resistor is
used to set the value of the current supplied to an external
load/termination resistor. The load resistor value is chosen to equal
the value of the characteristic line impedance of 50. The 851021 is
characterized at an operating supply voltage of 3.3V.
The differential HCSL outputs, accurate crossover voltage and duty
cycle make the 851021 ideal for interfacing to PCI Express and
FBDIMM applications.

Features
• Twenty-one differential HCSL outputs
• Translates any differential input signal (LVPECL, LVHSTL, LVDS,
HCSL) to HCSL levels without external bias networks
• Maximum output frequency: 250MHz
• Output skew: 395ps (maximum)
• Part-to-part skew: 335ps (maximum)
• Output drift: 140ps (maximum)
• VOH: 850mV (maximum)
• Full 3.3V supply voltage
• Available in lead-free (RoHS 6) package
• 0°C to 70°C ambient operating temperature