ADCLK944:  2.5 V/3.3 V, Four LVPECL Outputs, SiGe Clock Fanout Buffer

The ADCLK944 is an ultrafast clock fanout buffer fabricated on the Analog Devices, Inc., proprietary XFCB3 silicon germanium (SiGe) bipolar process. This device is designed for high speed applications requiring low jitter.

The device has a differential input equipped with center-tapped, differential, 100 Ω on-chip termination resistors. The input can accept dc-coupled LVPECL, CML, 3.3 V CMOS (single-ended), and ac-coupled 1.8 V CMOS, LVDS, and LVPECL inputs. A V_REF pin is available for biasing ac-coupled inputs.

The ADCLK944 features four full-swing emitter-coupled logic (ECL) output drivers. For LVPECL (positive ECL) operation, bias V_CC to the positive supply and V_EE to ground. For ECL operation, bias V_CC to ground and V_EE to the negative supply.

The ECL output stages are designed to directly drive 800 mV each side into 50 Ω terminated to V_CC − 2 V for a total differential output swing of 1.6 V.

The ADCLK944 is available in a 16-lead LFCSP and is specified for operation over the standard industrial temperature range of −40°C to +85°C. Applications

• Low jitter clock distribution
• Clock and data signal restoration
• Level translation
• Wireless communications
• Wired communications
• Medical and industrial imaging
• ATE and high performance instrumentation