DS2409 Datasheet, PDF (1/18 Pages) Dallas Semiconductor – MicroLAN Coupler

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DS2409
MicroLAN Coupler
FEATURES
§ Low impedance coupler to create large
common-ground, multi-level MicroLAN
networks
§ Keeps inactive branches pulled high to 5V
§ Simplifies network topology analysis by
logically decoupling devices on active
network segments
§ Conditional search for fast event signaling
§ Auxiliary 1-Wire^TM line to connect a memory
chip or to be used as digital input
§ Programmable, general purpose open drain
control output
§ Communicates at 16.3k bits per second
§ Unique, factory-lasered and tested 64-bit
registration number (8-bit family code + 48-
bit serial number + 8-bit CRC tester) assures
absolute traceability because no two parts are
alike
§ 8-bit family code specifies device
communication requirements to bus master
§ Built-in multidrop controller ensures
compatibility with other MicroLAN products
§ Operating temperature range from -40°C to
+85°C
§ Compact, low cost 6-pin TSOC surface mount
package
PIN ASSIGNMENT
6-PIN TSOC PACKAGE
16
25
34
TOP VIEW
3.7 X 4.0 X 1.5 mm
SIDE VIEW
PIN DESCRIPTION
Pin 1
GND
Pin 2
1-Wire in
Pin 3
Main 1-Wire out
Pin 4
Auxiliary 1-Wire out
Pin 5
Control Output
Pin 6
V_DD
ORDERING INFORMATION
DS2409P 6-pin TSOC package
DESCRIPTION
The MicroLAN coupler is an essential component to build and control 1-Wire MicroLAN networks with
multi-level branching. In contrast to approaches that switch the ground line, the coupler maintains a
common ground level for the whole network and keeps the inactive segments powered. This simplifies
supplying central or local power for additional circuitry and prevents loss of status of parasitically
powered devices. It also avoids disrupting communication caused by the parasitic power supply of 1-Wire
devices after activating a branch. The coupler does not contain any user-programmable memory. To label
a branch one can connect any 1-Wire memory device to the auxiliary 1-Wire output of the coupler. Both
the main and the auxiliary 1-Wire output are supported by a “smart-on” command. This command
generates a reset/presence sequence on the selected output before the electronic switch closes the contact
to the 1-Wire bus. This way the bus master can apply a ROM function command (optionally followed by
a memory function) to the devices on the just activated segment with all other devices in the network
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