Rainbow Electronics DS2506 - Manual (Page 25)

DS2506
25 of 25
AC ELECTRICAL CHARACTERISTICS OVERDRIVE SPEED
(V
PUP
=2.8V to 6.0V; -40°C to 70°C)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Time Slot t
SLOT
6 16 µs
Write 1 Low Time t
LOW1
1 2 µs
Write 0 Low Time t
LOW0
6 16 µs
Read Data Valid t
RDV
2 µs 12
Release Time t
RELEASE
0 1.5 4 µs
Read Data Setup t
SU
1 µs 5
Recovery Time t
REC
1 µs
Reset Time High t
RSTH
48 µs 4
Reset Time Low t
RSTL
48 80 µs
Presence Detect High t
PDHIGH
2 6 µs
Presence Detect Low t
PDLOW
8 24 µs
NOTES:
1. All voltages are referenced to ground.
2. V
PUP
= external pullup voltage.
3. Input load is to ground.
4. An additional reset or communication sequence cannot begin until the reset high time has expired.
5. Read data setup time refers to the time the host must pull the 1-Wire bus low to read a bit. Data is
guaranteed to be valid within 1 µs of this falling edge.
6. V
IH
is a function of the external pullup resistor and V
PUP
.
7. 30 nanocoulombs per 72 time slots @ 5.0V.
8. At V
CC
=5.0V with a 5 kΩ pullup to V
CC
and a maximum time slot of 120 µs.
9. Capacitance on the data pin could be 800 pF when power is first applied. If a 5 kΩ resistor is used to
pullup the data line to V
CC
, 5 µs after power has been applied the parasite capacitance will not affect
normal communications.
10. Under certain low voltage conditions V
ILMAX
may have to be reduced to as much as 0.5V to always
guarantee a presence pulse.
11. Operational temperature range for memory programming is -40 ° C to +50 ° C.
12. For read-data time slots the optimal sampling point for the master is as close as possible to the end
time of the t
RDV
period without exceeding 15 µs for regular speed or 2 µs for overdrive speed. For the
case of a read-one time slot, this maximizes the amount of time for the pull-up resistor to recover the
line to a high level. For a read-zero time slot it ensures that a read will occur before the fastest 1-Wire
device releases the line (t
RELEASE
= 0).