RX
-
8581
SA
/
JE
/
NB
Page - 4
MQ372-02
7.2. AC Characteristics
* Unless otherwise specified,
GND
=
0
V
,
V
DD
=
1.8
V
to
5.5
V
,
Ta
=
−
40
°
C
to
+85
°
C
Item Symbol
Condition
Min.
Typ.
Max.
Unit
SCL clock frequency
f
SCL
400
kHz
Start condition setup time
t
SU;STA
0.6
µ
s
Start condition hold time
t
HD;STA
0.6
µ
s
Data setup time
t
SU;DAT
100
ns
Data hold time
t
HD;DAT
0
ns
Stop condition setup time
t
SU;STO
0.6
µ
s
Bus idle time between
start condition and stop condition
t
BUF
1.3
µ
s
Time when SCL
=
"L"
t
LOW
1.3
µ
s
Time when SCL
=
"H"
t
HIGH
0.6
µ
s
Rise time for SCL and SDA
t
r
0.3
µ
s
Fall time for SCL and SDA
t
f
0.3
µ
s
Allowable spike time on bus
t
SP
50
ns
FOUT duty
t
W
/t
V
DD
=
2.4
V
∼
5.5
V
50% of V
DD
level
45 50 55 %
Timing chart
t
HD ; DAT
t
SU ; DAT
t
HD ; STA
t
LOW
t
HIGH
1 / f
SCL
t
r
t
f
t
SU ; STA
SDA
SCL
START
CONDITION
(S)
BIT 7
MSB
(A7)
BIT 6
(A6)
ACK
(A)
Protocol
t
BUF
t
SU ; STO
STOP
CONDITION
(P)
START
CONDITION
(S)
(P)
(A)
t
HD ; STA
t
SU ; STA
(S)
BIT 0
LSB
(R/W)
(S)
t
SP
Caution: When accessing this device, all communication from transmitting the start condition to transmitting the stop
condition after access
should be completed within 0.95 seconds
.
If such communication requires
0.95 seconds
or longer, the I
2
C bus interface is reset by the internal bus
timeout function.
