Rainbow Electronics DS1678 - Manual (Page 21)

DS1678
21 of 26
AC ELECTRICAL CHARACTERISTICS (-40 °C to +85°C, V
CC
= 4.5V to 5.5V)
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES
SCL Clock Frequency f
scl
Fast Mode
Standard Mode
100 400
100 kHz
Bus Free Time
Between a STOP and
START Condition t
buf
Fast Mode
Standard Mode
1.3
4.7 µs
Hold Time (Repeated)
START Condition. t
hd:sta
Fast Mode
Standard Mode
0.6
4.0 µs 1
LOW Period of SCL t
low
Fast Mode
Standard Mode
1.3
4.7 µs
HIGH Period of SCL t
high
Fast Mode
Standard Mode
0.6
4.0 µs
Set-Up Time for a
Repeated START t
su:sta
Fast Mode
Standard Mode
0.6
4.7 µs
Data Hold Time t
hd:dat
Fast Mode
Standard Mode
0
0 0.9 µs 2
Data Set-up Time t
su:dat
Fast Mode
Standard Mode
100
250 ns 3
Rise Time of Both
SDA and SCL Signals t
r
Fast Mode
Standard Mode
20 +
0.1C
b
300
1000
ns 4
Fall Time of Both
SDA and SCL Signals t
f
Fast Mode
Standard Mode
20 +
0.1C
b
300
300 ns 4
Set-up Time for STOP t
su:sto
Fast Mode
Standard Mode
0.6
4.0 µs
Capacitive Load for
Each Bus Line C
b
400 pF 4
Input Capacitance C
i
5 pF
DATA TRANSFER ON 2-WIRE SERIAL BUS Figure 3
MSB
slave address
R/W
direction
bit
SDA
SCL
START
CONDITION
1 2 6 7 8 9 1 2 8 9
STOP CONDITION
OR
REPEATED
START CONDITION
3 - 8
acknowledgement
signal from receiver
acknowledgement
signal from receiver
ACK ACK
repeated if more bytes
are transferred