DS1482 Datasheet, PDF (4/7 Pages) Dallas Semiconductor – 1-Wire Level Shifter and Line Driver with Load Sensor

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DS1482
The 1-Wire slave device starts drawing current (internal micro or numeric processor is
running). The strong pullup (SPU) must be activated before the high current phase begins.
The 1-Wire slave device no longer draws current. After the deglitching time (t_CF) is over, the
DONE signal turns high. The START signal must be activated no later than t_SD before t_CF is
over. Typically START is activated shortly after SPU, but not before the 1-Wire slave device
has started drawing high current.
As soon as the DONE signal is high, the host micro ends the strong pullup by changing SPU
to low.
While the DONE signal is high, the host micro changes START to low; this may occur
simultaneously with the state change of SPU or later. When START changes to low, DONE
becomes low.
Figure 5. Timing References TXD to I/O
TXD
I/O
t_TI
t_FIO
0.7 x V_CCQ
0.2 x V_CCQ
t_TI
0.9 x V_CC
0.1 x V_CC
Figure 6. Timing References I/O to RXD
I/O
t_IR
RXD
t_F
0.7 x V_CC
0.2 x V_CC
t_IR
0.9 x V_CCQ
0.1 x V_CCQ
t_R
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