Philips integrated circuits pdiusbh12 User Manual

Page of 28
Philips Semiconductors
Product specification
PDIUSBH12
USB 2-port hub
1999 Jul 22
23
AC CHARACTERISTICS (I
2
C pins)
All timing values are valid within the operating supply voltage and ambient temperature range and reference to V
IL
 and V
IH
 with an input voltage
swing of V
SS
 and V
DD
.
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
MAX
UNIT
f
SCL
SCL clock frequency
1000
kHz
t
BUF
Bus free time
0.5
µ
s
t
SU;STA
Start condition set-up time
0.25
µ
s
t
HD;STA
Start condition hold time
0.25
µ
s
t
LOW
SCL LOW time
0.45
µ
s
t
HIGH
SCL HIGH time
0.45
µ
s
t
r
SCL and SDA rise time
0.3
µ
s
t
f
SCL and SDA fall time
0.1
µ
s
t
SU;DAT
Data set-up time
100
ns
t
HD;DAT
Data hold time
0
ns
t
VD;DAT
SCL
 
LOW to data out valid
0.4
µ
s
t
SU;STO
Stop condition set-up time
0.25
µ
s
A detailed description of the I
2
C-bus specification, with applications, is given in the brochure “
The I
2
C-bus and how to use it
”. This brochure may
be ordered using the Philips order number 9398 393 40011.
SV00756
SCL
SDA
PROTOCOL
t
SU;STA
t
LOW
t
HIGH
1/f
SCL
t
BUF
t
r
t
f
t
HD;STA
t
SU;DAT
t
HD;DAT
t
VD:DAT
t
SU;STO
BIT 0
LSB
(R/W)
ACKNOWLEDGE
           (A)
      STOP
CONDITION
        (P)
    START 
CONDITION
       (S)
BIT 7
MSB
(A7)
BIT 6
 (A6)
Figure 4. I
2
C-bus timing diagram