B9947

Features:

• 160-MHz Clock Support
• LVCMOS/LVTTL Compatible Inputs
• 9 Clock Outputs: Drive up to 18 Clock Lines
• Synchronous Output Enable
• Output Three-state Control
• 350-ps Maximum Output-to-Output Skew
• Pin Compatible with MPC947
• Industrial Temp. Range: 40°C to +85°C
• 32-Pin TQFP Package


Specifications

Maximum Input Voltage Relative to VSS: ............  VSS 0.3V
Maximum Input Voltage Relative to VDD: .............VDD + 0.3V
Storage Temperature: ...........................65°C to + 150°C
Operating Temperature: ...........................40°C to +85°C
Maximum ESD protection .................................................2 KV
Maximum Power Supply: ..................................................5.5V
Maximum Input Current:.............................................±20 mA


Description

The B9947 is a low-voltage clock distribution buffer with the capability to select one of two LVCMOS/LVTTL compatible clock inputs. The two clock sources can be used to provide for a test clock as well as the primary system clock. All other con-trol inputs are LVCMOS/LVTTL compatible. The nine outputs are 3.3V LVCMOS or LVTTL compatible and can drive two series terminated 50Ω transmission lines. With this capability the B9947 has an effective fanout of 1:18. The outputs can also be three-stated via the three-state input TS#. Low out- put-to-output skews make the B9947 an ideal clock distribu- tion buffer for nested clock trees in the most demanding of synchronous systems.

The B9947 also provides a synchronous output enable input for enabling or disabling the output clocks. Since this input is internally synchronized to the input clock, potential output glitching or runt pulse generation is eliminated.