DS1961S
36 of 36
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS NOTES
SHA-1 ENGINE
Computation Current I
LCSHA
4.5 mA 14
Computation Time t
CSHA
1.5 ms
NOTES:
1) System requirement.
2) Maximum allowable pullup resistance is a function of the number of 1-Wire devices in the system
and 1-Wire recovery times. The specified value here applies to systems with only one device and
with the minimum 1-Wire recovery times. For more heavily loaded systems, an active pullup such
as that found in the DS2480B may be required.
3)
Capacitance on the data pin could be 800pF when power is first applied. If a 5kW resistor is used
to pull up the data line to V
PUP;
the parasite capacitance does not affect normal communications
5µs after power has been applied.
4) Input load is to ground.
5) All voltages are referenced to ground.
6) V
TL
, V
TH
are a function of the internal supply voltage.
7) Voltage below which, during a falling edge on I/O, a logic 0 is detected.
8) The voltage on I/O needs to be less or equal to V
ILMAX
whenever the master drives the line low.
9) Voltage above which, during a rising edge on I/O, a logic 1 is detected.
10) The I-V characteristic is linear for voltages less than 1V.
11)
e is the time required for the pullup circuitry to pull the voltage on I/O up from V
IL
to V
TH
.
12)
d represents the time required for the pullup circuitry to pull the voltage on I/O up from V
IL
to the
input high threshold of the bus master.
13) Highlighted numbers are not in compliance with the published iButton standards. See comparison
table below.
14) Guaranteed by design, not production tested
STANDARD VALUES DS1961S VALUES
PARAMETER STANDARD
SPEED
OVERDRIVE
SPEED
STANDARD
SPEED
OVERDRIVE
SPEED
NAME MIN MAX MIN MAX MIN MAX MIN MAX
t
SLOT
(incl. t
REC
) 61µs (undef.) 7µs (undef.) 65µs (undef.) 9µs (undef.)
t
RSTL
480µs (undef.) 48µs 80µs 720µs 960µs 68µs 80µs
t
PDH
15µs 60µs 2µs 6µs 15µs 60µs 1µs 6.7µs
t
PDL
60µs 240µs 8µs 24µs 60µs 285µs 7.3µs 24µs
t
W0L
60µs 120µs 6µs 16µs 60µs 120µs 7µs 14µs
t
SLS
, t
SPD
15µs 60µs 2µs 6µs 15µs 60µs 1.85µs 7µs
