Datasheet

DS1904
12 of 13
NOTES:
1. All voltages are referenced to ground.
2. V
PUP
= external pull-up voltage; see Figure 6.
3. Input load is to ground.
4. 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.
5. Under certain low voltage conditions V
IL1MAX
may have to be reduced to as much as 0.5V to always
guarantee a presence pulse.
6. 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.
7. The master must read while the data is valid.
8. Guaranteed by design; not production tested.
9. This specification applies if the 1-Wire is idle (high or low). Communication on the 1-Wire may
adversely affect the accuracy of the device. For highest accuracy, connect the DS1904 to a separate
1-Wire port and limit the access to the minimum acceptable by the application.
PACKAGE INFORMATION
For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the
drawing pertains to the package regardless of RoHS status.
PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
F5 iButton IB#5CB
21-0266
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