ICS87951I
LOW SKEW, 1-TO-9
DIFFERENTIAL-TO-LVCMOS/LVTTL ZERO DELAY BUFFER
Integrated
Circuit
Systems, Inc.
PARAMETER MEASUREMENT INFORMATION
1.65V 5ꢂ
VDD
SCOPE
VDDA
VDDO
,
nCLK1
Qx
VPP
VCMR
Cross Points
LVCMOS
GND
CLK1
GND
-1.65V 5ꢂ
3.3V OUTPUT LOAD AC TEST CIRCUIT
DIFFERENTIAL INPUT LEVEL
VDDO
2
VDDO
2
VDDO
2
VDDO
QA,
QB,
QCx,
QDx
Qx
Qy
2
➤
➤
tcycle n+1
tcycle n
➤
➤
VDDO
2
tjitꢀccꢁ = tcycle n –tcycle n+1
tskꢀoꢁ
1000 Cycles
CYCLE-TO-CYCLE JITTER
OUTPUT SKEW
nCLK1
VOH
VOL
2V
2V
CLK0,
CLK1
0.8V
0.8V
VOH
Clock
VDDO
VO2L
tR
tF
Outputs
EXT_FB
➤
tꢀØꢁ
➤
tjitꢀØꢁ = tꢀØꢁ — tꢀØꢁ mean = Phase Jitter
tꢀØꢁ mean = Static Phase Offset
OUTPUT RISE/FALL TIME
VDDO
2
VDDO
VDDO
ꢀwhere tꢀØꢁ is any random sample, and tꢀØꢁ mean is the average
of the sampled cycles measured on controlled edgesꢁ
2
2
QA,
QB,
QCx,
QDx
tPW
tPERIOD
tPW
tPERIOD
odc =
PHASE JITTER AND STATIC PHASE OFFSET
OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
87951AYI
www.icst.com/products/hiperclocks.html
REV.B NOVEMBER 23, 2005
7