DS2408_10 Datasheet, PDF (1/39 Pages) Maxim Integrated Products – 1-Wire 8-Channel Addressable Switch

19-5702; 12/10
www.maxim-ic.com
DS2408
1-Wire 8-Channel Addressable Switch
FEATURES
 Eight Channels of Programmable I/O with
Open-Drain Outputs
 On-Resistance of PIO Pulldown Transistor
100Ω (max); Off-Resistance 10MΩ (typ)
 Individual Activity Latches Capture
Asynchronous State Changes at PIO Inputs for
Interrogation by the Bus Master
 Data-Strobe Output to Synchronize PIO Logic
States to External Read/Write Circuitry
 Built-in Multidrop Controller Ensures
Compatibility with Other Dallas Semiconductor
1-Wire^® Net Products
 Supports 1-Wire Conditional Search Command
with Response Controlled by Programmable
PIO Conditions
 Unique Factory-Lasered 64-Bit Registration
Number Ensures Error-Free Device Selection
and Absolute Part Identity
 Communicates to Host with a Single Digital
Signal at 15.3kbps or 100kbps using 1-Wire
Protocol
 Operating Range: 2.8V to 5.25V, -40°C to
+85°C
PIN CONFIGURATION
150-mil SO
ORDERING INFORMATION
PART
TEMP RANGE
DS2408S+
-40°C to +85°C
DS2408S+T&R -40°C to +85°C
+Denotes a lead(Pb)-free package.
T&R = Tape and reel.
PIN-PACKAGE
16 SO
16 SO
DESCRIPTION
The DS2408 is an 8-channel, programmable I/O 1-Wire chip. PIO outputs are configured as open-drain and
provide an on resistance of 100Ω max. A robust PIO channel-access communication protocol ensures that PIO
output-setting changes occur error-free. A data-valid strobe output can be used to latch PIO logic states into
external circuitry such as a D/A converter (DAC) or microcontroller data bus.
DS2408 operation is controlled over the single-conductor 1-Wire bus. Device communication follows the
standard Dallas Semiconductor 1-Wire protocol. Each DS2408 has its own unalterable and unique 64-bit
ROM registration number that is factory lasered into the chip. The registration number guarantees unique
identification and is used to address the device in a multidrop 1-Wire net environment. Multiple DS2408
devices can reside on a common 1-Wire bus and can operate independently of each other. The DS2408 also
supports 1-Wire conditional search capability based on PIO conditions or power-on-reset activity; the
conditions to cause participation in the conditional search are programmable. The DS2408 has an optional V_CC
supply connection. When an external supply is absent, device power is supplied parasitically from the 1-Wire
bus. When an external supply is present, PIO states are maintained in the absence of the 1-Wire bus power
source. The RSTZ signal is configurable to serve as either a hard-wired reset for the PIO output or as a strobe
for external circuitry to indicate that a PIO write or PIO read has completed.
1-Wire is a registered trademark of Maxim Integrated Products, Inc. _{1 of 39}