
DS2506
25 of 25
AC ELECTRICAL CHARACTERISTICS OVERDRIVE SPEED
(VPUP=2.8V to 6.0V; -40°C to 70°C)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
Time Slot
tSLOT
616
s
Write 1 Low Time
tLOW1
12
s
Write 0 Low Time
tLOW0
616
s
Read Data Valid
tRDV
2s
12
Release Time
tRELEASE
0
1.5
4
s
Read Data Setup
tSU
1s
5
Recovery Time
tREC
1s
Reset Time High
tRSTH
48
s
4
Reset Time Low
tRSTL
48
80
s
Presence Detect High
tPDHIGH
26
s
Presence Detect Low
tPDLOW
824
s
NOTES:
1. All voltages are referenced to ground.
2. VPUP= 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 s of this falling edge.
6. VIH is a function of the external pullup resistor and VPUP.
7. 30 nanocoulombs per 72 time slots @ 5.0V.
8. At VCC=5.0V with a 5 k pullup to VCC and a maximum time slot of 120 s.
9. Capacitance on the data pin could be 800 pF when power is first applied. If a 5 k resistor is used to
pullup the data line to VCC, 5 s after power has been applied the parasite capacitance will not affect
normal communications.
10. Under certain low voltage conditions VILMAX 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 tRDV period without exceeding 15 s for regular speed or 2 s 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 (tRELEASE = 0).