DS2505PTR Dallas Semiconducotr, DS2505PTR Datasheet - Page 24

• Manufacturer Part Number: DS2505PTR
• Description: 16-kbit Add-Only Memory
• Manufacturer: Dallas Semiconducotr

NOTES:
1. All voltages are referenced to ground.
2. V
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
6. V
7. 30 nanocoulombs per 72 time slots @ 5.0V.
8. At V
9. Capacitance on the data pin could be 800 pF when power is first applied. If a 5 k resistor is used to
10. Under certain low voltage conditions V
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 of
may not reproduce the correct memory contents. Therefore, under low voltage conditions, it is
recommended to set either the most significant bit or all five most significant bits of TA2 to 1.
Internal circuitry of the chip will force these 5 bits back to 0 before they are shifted in the address
counter and CRC generator.
guaranteed to be valid within 1 µs of this falling edge and will remain valid for 14 µs minimum.
(15 µs total from falling edge on 1-Wire bus.)
pull up the data line to V
normal communications.
guarantee a presence pulse.
the t
maximizes the amount of time for the pull-up resistor to recover the line to a high land. For a read-
zero time slot it ensures that a read will occur before the fastest 1-Wire device releases the line
(t
RELEASE
PUP
IH
is a function of the external pullup resistor and V
RDV
CC
= external pullup voltage. If V
=5.0V with a 5 k pullup to V
period without exceeding the 15 µs window. For the case of a read-one time slot, this
= 0)
CC
, 5 µs after power has been applied the parasite capacitance will not affect
CC
PUP
ILMAX
and a maximum time slot of 120 µs.
is lower than 3.0V the first byte read (any read command)
may have to be reduced to as much as 0.5V to always
24 of 24
PUP
.