Datasheet

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SBOS288J − JANUARY 2004 − REVISED DECEMBER 2007
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10
TIMING DIAGRAMS
The TMP175 and TMP75 are Two-Wire and SMBus
compatible. Figure 4 to Figure 8 describe the various
operations on the TMP175 and TMP75. Bus definitions are
given below. Parameters for Figure 4 are defined in
Table 13.
Bus Idle: Both SDA and SCL lines remain HIGH.
Start Data Transfer: A change in the state of the SDA line,
from HIGH to LOW, while the SCL line is HIGH, defines a
START condition. Each data transfer is initiated with a
START condition.
Stop Data Transfer: A change in the state of the SDA line
from LOW to HIGH while the SCL line is HIGH defines a
STOP condition. Each data transfer is terminated with a
repeated START or STOP condition.
Data Transfer: The number of data bytes transferred
between a START and a STOP condition is not limited and
is determined by the master device. The receiver
acknowledges the transfer of data.
Acknowledge: Each receiving device, when addressed,
is obliged to generate an Acknowledge bit. A device that
acknowledges must pull down the SDA line during the
Acknowledge clock pulse in such a way that the SDA line
is stable LOW during the HIGH period of the Acknowledge
clock pulse. Setup and hold times must be taken into
account. On a master receive, the termination of the data
transfer can be signaled by the master generating a
Not-Acknowledge on the last byte that has been
transmitted by the slave.
PARAMETER
FAST MODE HIGH-SPEED MODE
UNITS
PARAMETER
MIN MAX MIN MAX
UNITS
SCL Operating Frequency f
(SCL)
0.001 0.4 0.001 3.4 MHz
Bus Free Time Between STOP and START Condition t
(BUF)
600 160 ns
Hold time after repeated START condition.
After this period, the first clock is generated.
t
(HDSTA)
100 100 ns
Repeated START Condition Setup Time t
(SUSTA)
100 100 ns
STOP Condition Setup Time t
(SUSTO)
100 100 ns
Data Hold Time t
(HDDAT)
0 0 ns
Data Setup Time t
(SUDAT)
100 10 ns
SCL Clock LOW Period t
(LOW)
1300 160 ns
SCL Clock HIGH Period t
(HIGH)
600 60 ns
Clock/Data Fall Time t
F
300 160 ns
Clock/Data Rise Time t
R
300 160 ns
for SCLK ≤ 100kHz t
R
1000 ns
Table 13. Timing Diagram Definitions for the TMP175 and TMP75
TWO-WIRE TIMING DIAGRAMS
SCL
SDA
t
(LOW)
t
R
t
F
t
(HDSTA)
t
(HDSTA)
t
(HDDAT)
t
(BUF)
t
(SUDAT)
t
(HIGH)
t
(SUSTA)
t
(SUSTO)
PS SP
Figure 4. Two-Wire Timing Diagram