Owner's manual

DS1957
25 of 25
AC ELECTRICAL CHARACTERISTICS
OVERDRIVE SPEED (V
PUP
=4.0V to 5.5V; -20°C to +70°C)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Time Slot t
SLOT
616µs
Write 1 Low Time t
LOW1
12µs
Write 0 Low Time t
LOW0
616µs
Read Low Time t
LOWR
12µs
Read Data Valid t
RDV
exactly 2 µs
Release Time t
RELEASE
0 1.5 4 µs
Read Data Setup t
SU
1µs5
Recovery Time t
REC
1µs
Reset Time High t
RSTH
48 µs 4
Reset Time Low t
RSTL
48 80 µs
Presence Detect High t
PDHIGH
26µs
Presence Detect Low t
PDLOW
824µs
NOTES:
1. All voltages are referenced to ground.
2. V
PUP
= external pull-up 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. Capacitance on the data pin could be 150 nF when power is first applied. If a 1.5 kΩ resistor is used
to pull up the data line to V
CC
, 500 µs after power has been applied, the parasite capacitance will not
affect normal communications.
7. The reset low time (t
RSTL
) should be restricted to a maximum of 960 µs, to allow interrupt signaling,
otherwise, it could mask or conceal interrupt pulses.