Philips Semiconductors
Product specification
PDIUSBH12
USB 2-port hub
1999 Jul 22
21
AC CHARACTERISTICS (AI/O pins, LOW speed)
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
MAX
UNIT
Driver characteristics
C
L
= 50pF and 350pF;
R
pu
= 1.5k
Ω
on D– to V
CC
Transition Time
Between 10% and 90%
t
Rise time
C
L
= 50pF
75
ns
t
lr
Rise time
C
L
= 350pF
300
ns
t
f
Fall time
C
L
= 50pF
75
ns
t
lf
Fall time
C
L
= 350pF
300
ns
t
RFM
Rise/fall time matching
(t
r
/t
f
)
80
120
%
V
LCRS
Output signal crossover voltage
1.3
2.0
V
Driver Timings
t
LEOPT
Source EOP width
Figure 1
1.25
1.50
µ
s
t
LDEOP
Differential data to EOP transition skew
Figure 1
–40
100
ns
Receiver Timings
EOP Width at Receiver
t
LEOPR1
Must reject as EOP
Figure 1
330
ns
t
LEOPR2
Must accept
Figure 1
675
ns
Hub Timings
Low Speed downstream port.
t
LHDD
Hub Differential Data Delay
Figure 2
300
ns
t
LSOP
Data bit width distortion after SOP
Figure 2
–65
45
ns
t
LEOPDR
Hub EOP Delay Relative to T
HDD
Figure 3
0
200
ns
t
LHESK
Hub EOP Output Width Skew
Figure 3
–300
+300
ns
SV00837
t
PERIOD
DIFFERENTIAL
DATA LINES
CROSSOVER POINT
CROSSOVER POINT
EXTENDED
DIFFERENTIAL DATA TO
SEO/EOP SKEW
N * t
PERIOD
+ t
DEOP
SOURCE EOP WIDTH: t
EOPT
RECEIVER EOP WIDTH: t
EOPR1
, t
EOPR2
Figure 1. Differential data to EOP transition skew and EOP width
