DS2422 Maxim, DS2422 Datasheet - Page 41

• Manufacturer Part Number: DS2422
• Description: The DS2422 temperature/data logger combines the core functions of a fully featured data logger in a single chip
• Manufacturer: Maxim

Master-to-Slave
For a write-one time slot, the voltage on the data line must have crossed the V
low time t
threshold until the write-zero low time t
line should not exceed V
DS2422 needs a recovery time t
Figure 16. Read/Write Timing Diagram
Write-One Time Slot
Write-Zero Time Slot
Read-Data Time Slot
Slave-to-Master
A read-data time slot begins like a write-one time slot. The voltage on the data line must remain below V
read low time t
line low; its internal timing generator determines when this pulldown ends and the voltage starts rising again. When
responding with a 1, the DS2422 will not hold the data line low at all, and the voltage starts rising as soon as t
over.
W1LMAX
V
V
V
IHMASTER
IHMASTER
IHMASTER
V
V
V
RL
V
V
V
ILMAX
ILMAX
ILMAX
V
V
V
V
V
V
PUP
PUP
PUP
0V
0V
0V
is expired. During the t
is expired. For a write-zero time slot, the voltage on the data line must stay below the V
TH
TH
TH
TL
TL
TL
t
F
t
t
F
F
ILMAX
RESISTOR
RESISTOR
RESISTOR
during the entire t
t
RL
t
REC
W1L
before it is ready for the next time slot.


W0LMIN
RL
window, when responding with a 0, the DS2422 will start pulling the data
Sampling
is expired. For most reliable communication the voltage on the data
Window
Master
W0L
t
W0L
t
MSR
or t
41 of 49
W1L
MASTER
MASTER
MASTER
t
SLOT
window. After the V
t
t
SLOT
SLOT

TH
TH
threshold has been crossed, the
t
REC
DS2422
threshold before the write-one
t
REC
TL
until the
RL
TH
is