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ADVANCED INFORMATION
describes products that are not in full production at the time of printing. Specifications are based on design goals
and limited characterization. They may change without notice. Contact Fairchild Semiconductor for current information.
www.fairchildsemi.com
Features
18 skew controlled outputs
Supports up to four SDRAM DIMMs
Skew between any two outputs is less than 250 pS
¥
I
2
C Serial Interface for programming options
Multiple power and ground pins for noise reduction
Single 3.3V power supply
48 Pin SSOP package
Applications
SDRAM Clock Buffers for Intel’s 440BX chip set
Description
The RC7101 is a low voltage eighteen output clock buffer
which supports 4 DIMMs. The skew between any two out-
puts is less than 250 pS and the buffers can be individually
enabled or disabled by programming via the I
2
C serial inter-
face. The SDATA and SCLK serial inputs both have internal
pull-up resistors.
An Output Enable (OE) pin is also provided so that all the
outputs can be tri-stated when held low. This pin is normally
high and has an internal pull-up resistor.
OE
0
1
SDRAM0:3 SDRAM4:7 SDRAM8:11 SDRAM12:15 SDRAM16:17
Hi-Z
Hi-Z
Hi-Z
BUF_IN
BUF_IN
BUF_IN
Hi-Z
BUF_IN
Hi-Z
BUF_IN
Block Diagram
BUF_IN
SDRAM0
SDRAM1
SDRAM2
I
2
C
SDRAM3
SDRAM4
SDRAM5
SDRAM6
SDRAM7
SDRAM8
SDRAM9
SDRAM10
SDRAM11
SDRAM12
SDRAM13
SDRAM14
SDRAM15
SDRAM16
SDRAM17
SDATA
SCLOCK
OE
RC7101
Low S kew Buffers
100MHz SDRAM Clock Buffers
Rev. 0.5.2