User Manual

AC Electrical Characteristics
The following specifications apply for +2.8V
DC
≤ V
+
≤ +3.8V
DC
on SMBCLK and SMBData, unless otherwise specified. Bold-
face limits apply for T
A
=T
J
=T
MIN
to T
MAX
; all other limits T
A
=T
J
= 25˚C. (Note 15)
Symbol Parameter Conditions Typical Limits Units
(Note 9) (Note 10) (Limits)
SERIAL BUS TIMING CHARACTERISTICS
t
1
SMBCLK (Clock) Period 2.5 µs (min)
t
rise
SMBCLK and SMBData Rise Time 1 µs (max)
t
fall
SMBCLK and SMBData Fall Time 300 ns (max)
t
2
Data In Setup Time to SMBCLK High 100 ns (min)
t
3
Data Out Stable After SMBCLK Low 0 ns (min)
t
4
SMBData Low Setup Time to SMBCLK Low
(start)
100 ns (min)
t
5
SMBData High Hold Time After SMBCLK
High (stop)
100 ns (min)
t
TIMEOUT
SMBData or SMBCLK low time required to
reset the Serial Bus Interface to the Idle
State
31
25
35
ms
ms (min)
ms (max)
C
L
Capacitive Load on SMBCLK and SMBData 400 pF (max)
DS100072-4
FIGURE 1. Serial Bus Timing Diagram
LM81
www.national.com 8