Datasheet

MAX395
Serially Controlled, Low-Voltage,
8-Channel SPST Switch
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8x1 Multiplexer
To use the MAX395 as an 8x1 multiplexer, connect all
common pins together (COM0–COM7) to form the mux
output; the mux inputs are NO0–NO7.
The mux can be programmed normally, with only one
channel selected for every eight clock pulses, or it can
be programmed in a fast mode, where channel chang-
ing occurs on each clock pulse. In this mode, the chan-
nels are selected by sending a single high pulse
(corresponding to the selected channel) at DIN, and a
corresponding CS low pulse for every eight clock puls-
es. As this is clocked through the register by SCLK,
each switch sequences one channel at a time, starting
with Channel 7.
Dual, Differential 4-Channel Multiplexer
To use the MAX395 as a dual (4x2) mux, connect
COM0–COM3 together and connect COM4–COM7
together, forming the two outputs. The mux input pairs
become NO0/NO4, NO1/NO5, NO2/NO6, and NO3/NO7.
The mux can be programmed normally, with only one
differential channel selected for every eight clock puls-
es, or it can be programmed in a fast mode, where
channel changing occurs on each clock pulse.
In fast mode, the channels are selected by sending two
high pulses spaced four clock pulses apart (corre-
sponding to the two selected channels) at DIN, and a
corresponding CS low pulse for each of the first eight
clock pulses. As this is clocked through the register by
SCLK
DIN
DOUT
CS

SK
SO
SI
I/O
MICROWIRE
PORT
MAX395

THE DOUT-SI CONNECTION IS NOT REQUIRED FOR WRITING TO THE
MAX395, BUT MAY BE USED FOR DATA-ECHO PURPOSES.
Figure 3. Connections for Microwire
DOUT
DIN
SCLK
CS
MISO
MOSI
SCK
I/O
SPI
PORT
MAX395
THE DOUT-MISO CONNECTION IS NOT REQUIRED FOR WRITING TO THE
MAX395, BUT MAY BE USED FOR DATA-ECHO PURPOSES.
CPOL = 0, CPHA = 0
Figure 4. Connections for SPI and QSPI
SCLK
DIN
CS
MAX395
SCLK
DIN
CS
MAX395
SCLK
DIN
CS
MAX395
DOUT DOUT DOUT
SCLK
DIN
CS
TO OTHER
SERIAL DEVICES
Figure 5. Daisy-Chained Connection