ISL54400, ISL54401, ISL54402
Test Circuits and Waveforms
(Continued)
V
DD
C
1.3V< V
CM
< 2V
Dx or L or R or Nx
OUT +
V
CM
IN
IMPEDANCE
ANALYZER
COM
90%
10%
t
R
90%
10%
t
F
V
BUS
or V
IN
OUT -
GND
t
M
= | t
R
-t
F |
min (t
R
or t
F
)
Repeat test for all witches. COM designation in diagram
refers to:
D-/L, D+/R, COM1, and COM2.
FIGURE 5. CAPACITANCE TEST CIRCUIT
FIGURE 6. RISE/FALL TIME MISMATCH TEST
t
ri
90%
DIN+
DIN-
10%
50%
t
skew_i
90%
50%
10%
t
fi
t
ro
90%
OUT+
OUT-
10%
50%
t
skew_o
90%
t
f0
50%
10%
DIN-
DIN+
R
S
V
DD
C
D+/R
D+
OUT+
C
L
R
S
D-/L
D-
OUT-
C
L
GND
|tro - tri| Delay Due to Switch for Rising Input and Rising Output Signals.
|tfo - tfi| Delay Due to Switch for Falling Input and Falling Output Signals.
|tskew_0| Change in Skew through the Switch for Output Signals.
|tskew_i| Change in Skew through the Switch for Input Signals.
FIGURE 7A. MEASUREMENT POINTS
FIGURE 7. SKEW TEST
FIGURE 7B. TEST CIRCUIT
9
FN6240.3
July 12, 2006